Whats the point of buying a 110w radio?

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g8tzl2004
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Whats the point of buying a 110w radio?

Post by g8tzl2004 »

Motorola make a number of high power 110w radios as well as 50w medium power radios.

The 110w radios are generally trunk mounted with remote heads given the size of heatsinks required for 110w operation.

However, in the real world, whats the point of using 110w when you will get practically identical results running 50w?

In db terms, 110w represents only a 3.4dB increase in power...which is not much.

In fact, with some Motorola radios there is a more than 3dB variation in RX sensitivity...so you would be better of making sure you had a "hot" receiver.

Indeed , with the XTL5000, you have the option to "enable" a 4dB (I think) pre-amp. So rather than run a 110w radio you actually would be better of using a 50w radio with the 4dB pre-amp enabled!!! ie you could hear a 50w signal at greater distance with the 4dB pre-amp enabled vs a 110w signal without using the pre-amp.

I wonder how many are using XTL's without realising that Motorola has deliberately made them "deaf" until you update the flashcode. All my Jedi MCS2000's already have the "pre-amp" enabled as per standard....and the front ends are really hot. Has anybody compared an MCS2000 to an XTL with or without the pre-amp enabled?

Any views?
Last edited by g8tzl2004 on Wed Jun 11, 2014 11:13 am, edited 1 time in total.
jhooten
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Re: Whats the point of buying a 110w radio?

Post by jhooten »

A preamp or hot rx does nothing to help dispatch hear you.

Better to have it and not need it than to need it and not have it.

Mine is bigger than yours.
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escomm
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Re: Whats the point of buying a 110w radio?

Post by escomm »

Uh, the preamp only affects receive. So a 110 watt radio with no preamp will put out 60 more watts than a 50 watt radio with the preamp.

You will certainly notice the more than 3dB increase in output power on a 110 watt radio vs 50 watt... when you're out on the fringe. If you're in the middle of the sticks, every little bit can help.

Your assumptions are entirely off base and therefor the conclusions you have arrived at are also entirely off base.
RFguy
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Re: Whats the point of buying a 110w radio?

Post by RFguy »

g8tzl2004 wrote:In db terms, 110w represents only a 3.4dB increase in power...which is not much.
3.4 dB increase in power = 48% more range base solely on free space path loss (6 dB is 2 x distance base solely on free space path loss).
g8tzl2004
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

Assume dispatch is using a 110w XTL5000 BUT the dispatch RX pre-amp is NOT enabled.

If dispatch is having difficulty hearing 50w XTL5000 mobiles in the middle of the sticks then a better and cheaper solution would be to enable the dispatch XTL5000 4dB pre-amp rather than suggesting that all the 50w mobiles are replaced with new 110w mobiles.

Every little bit helps but optimising the dispatch RX side by enabling the pre-amp would actually have better results than replacing the entire mobile fleet with 110w radios (4 - 3.4dB = +0.6dB) Of course you could do both for even better coverage, but its much cheaper to just enable the dispatch pre-amp rather than replace hundreds of 50w XTL's with 110w XTL's

Mine is more sensitive than yours!!
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Re: Whats the point of buying a 110w radio?

Post by RFguy »

g8tzl2004 wrote:If dispatch is having difficulty hearing 50w XTL5000 mobiles in the middle of the sticks then a better and cheaper solution would be to enable the dispatch XTL5000 4dB pre-amp rather than suggesting that all the 50w mobiles are replaced with new 110w mobiles.
Better? Maybe not.

Selectivity vs sensitivity

Preamps are generally bad news in base stations. What's the noise floor like? Is there any other transmitters on-site. A pre-amp is broadband and will increase everything, including wanted and unwanted signals. If there are any strong adjacent channel signals, a pre-amp will result in increased front-end overloading.
g8tzl2004
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

Agreed...but you get what I'm trying to say...optimise the RX side before cranking up the power.

In real world tests, I have always found that increasing the TX power from 50 to 100W only makes a very marginal difference. I don't think I've ever achieved a 50% increase in range!!!
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Re: Whats the point of buying a 110w radio?

Post by sjxts3000 »

g8tzl2004 wrote:However, in the real world, whats the point of using 110w when you will get practically identical results running 50w?
You must live in a very flat area with not a lot of tall buildings.
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Re: Whats the point of buying a 110w radio?

Post by N4KVE »

I moved 50 miles north from where I used to live. While I can hear the same repeater I used for years, I couldn't quite get into it. Picked up a 100 watt MCS2000, & now nobody has troubles hearing me. When I get closer, I drop the radio to low power. Now the radio sits in a closet because the repeater owner set up a DMR system linking 7 repeaters in Florida. HT coverage instead of a 100 watt radio. Love those XPR radios. GARY
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Re: Whats the point of buying a 110w radio?

Post by talviar »

g8tzl2004 wrote:Assume dispatch is using a 110w XTL5000 BUT the dispatch RX pre-amp is NOT enabled.

If dispatch is having difficulty hearing 50w XTL5000 mobiles in the middle of the sticks then a better and cheaper solution would be to enable the dispatch XTL5000 4dB pre-amp rather than suggesting that all the 50w mobiles are replaced with new 110w mobiles.

Every little bit helps but optimising the dispatch RX side by enabling the pre-amp would actually have better results than replacing the entire mobile fleet with 110w radios (4 - 3.4dB = +0.6dB) Of course you could do both for even better coverage, but its much cheaper to just enable the dispatch pre-amp rather than replace hundreds of 50w XTL's with 110w XTL's

Mine is more sensitive than yours!!
Hmm. . . . . My dispatch center uses Motorola Quantar Base stations running at 125 Watts. Squelch is set at 100% and one of our receivers actually had to be detuned slightly to overcome the noise floor at the mountain top tower site we are on. Noise floor on a spectrum analyzer at site connected to base antenna runs at -95 dB--lots of noise. With that said regarding our high noise floor- A preamp is pretty much useless. When we were using that base for 2 ways comms (delegated to paging only as all users migrated to the county 800 MHz Trunking system in 1996) 50 watt mobiles routinely had issues making it in over top of all the stuff the site picked up. 110 W mobiles were the better option.

The balance of whether a pre-amp is needed (or will do anything) and what power output is needed to achieve desired talk in is best left to the folks using and operating the system. (And before I hear anyone else again say "it's only 3db". . . . there have been cases where a difference of 5 watts on the mobile made the difference between night and day. Radio running 40 watts couldn't talk in but running 45 watts talked in fine. hell of a difference there. . . . approximately 1/2 db difference. . . . )

As always this has been my $2.25 and YMMV!
jhooten
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Re: Whats the point of buying a 110w radio?

Post by jhooten »

g8tzl2004 wrote:Assume dispatch is using a 110w XTL5000 BUT the dispatch RX pre-amp is NOT enabled.

If dispatch is having difficulty hearing 50w XTL5000 mobiles in the middle of the sticks then a better and cheaper solution would be to enable the dispatch XTL5000 4dB pre-amp rather than suggesting that all the 50w mobiles are replaced with new 110w mobiles.

Every little bit helps but optimising the dispatch RX side by enabling the pre-amp would actually have better results than replacing the entire mobile fleet with 110w radios (4 - 3.4dB = +0.6dB) Of course you could do both for even better coverage, but its much cheaper to just enable the dispatch pre-amp rather than replace hundreds of 50w XTL's with 110w XTL's

Mine is more sensitive than yours!!

I've never been in a dispatch center that used a mobile radio for primary dispatch operations. Not to say it doesn't happen, but I have never seen it done. The consolettes were always a back up system.

The base stations main advantage is antenna height. Mobiles cannot take advantage of that means of improving communications range.

Putting a preamp on a base station receiver without having a good preselector in front of it will do more harm than good more times than not.

Mobile or base preamps amplify the noise as much as the signal. Signal to noise ratio/readability is not necessarily improved simply by adding a preamp.

A technician that knows how to properly tune the receiver will do much more to improve sensitivity than sticking a preamp in line.

Antenna and feed line quality will do more to improve signal quality than a preamp and will improve both sides of the path.
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escomm
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Re: Whats the point of buying a 110w radio?

Post by escomm »

RFguy wrote:Preamps are generally bad news in base stations. What's the noise floor like? Is there any other transmitters on-site. A pre-amp is broadband and will increase everything, including wanted and unwanted signals. If there are any strong adjacent channel signals, a pre-amp will result in increased front-end overloading.
So very true. Garbage in = garbage out.
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Bill_G
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Re: Whats the point of buying a 110w radio?

Post by Bill_G »

g8tzl - You're thinking all the right things. 3db is only 3db which is not a lot in the real world. As has been pointed out already, whether you get that 3db from an improved rcvr, by brute force with a transmitter, from antenna gain, by antenna height, or a combination of all of the above, depends on the situation. That 3db always comes into play in the last mile, and if that last mile is where you are working, then you get it any way you can.
com501
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Re: Whats the point of buying a 110w radio?

Post by com501 »

Where I live, the repeaters are anywhere up to 150 miles away in the mountains. 110w mobiles with preamps AND 3db gain antennas at VHF are the norm. 50w radios don't cut it. We LIVE in the last mile.
Will
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Re: Whats the point of buying a 110w radio?

Post by Will »

And the Desert sucks up radio signals.....
g8tzl2004
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

I guess my main point is that Motorola needs to sort out the massive variability in receiver sensitivity between identical radios.

The current spec of "better than 0.3uv for 12dB SINAD" (ie 117dBm) is not good enough. The spec allows sub standard "deaf" radios to be passed. With modern production techniques it must be possible to make sure each radio has more or less identical receive sensitivity.

My experience is that out of 6 identical radios, 1 will be hot (125dBm), 4 average (122dBm) and 1 deaf! (117dBm)!!!....but they are all still "in spec".

There is a massive 8dBm variation between a "hot" receiver and a "deaf" receiver..but the deaf receiver is still in spec.

Here's another theoretical example.

Say a user operating in the "last mile" has an in spec receiver but sensitivity is only 0.3uV for 12dB SINAD (ie 117dBm). He cannot hear the 50W base so its increased to 110W and he also gets a 110W radio. He can now just hear the base.

However, another user has an identical 50W radio but his receiver is hot ie 0.13uV for 12 dB SINAD (125dBm). Instead of the base having to increase power from 50 to 110W so that it can be heard in the last mile, the base could infact LOWER its power to just 17.4W!!!!!!

In other words, an in spec but "deaf" receiver needs the base to transmit 110W but an identical "hot" receiver needs the base to run just 17.4W for identical results.

Maybe Motorola should be made to print out the actual receiver sensitivity of each radio on the label on the side of the box!!!!
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Re: Whats the point of buying a 110w radio?

Post by N4KVE »

I have 2 identical 438-470 motorcycle Spectra's very close in serial #. One has a "hot" receiver, while the other isn't so hot, but in spec. The repeater I needed to use was 60 miles away, & while the 1st radio could hear it well, the 2nd was noisy. I asked Will to install the components used for the factory preamp in the 2nd radio. He did, & now the 2nd radio was as good as the 1st radio which had no preamp. Both radios would have been fine for a local repeater, but I needed to hit that Miami repeater from West Palm Beach. And yes, if I lived 10 miles south, this would not have been necessary. GARY
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Bill_G
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Re: Whats the point of buying a 110w radio?

Post by Bill_G »

It's called parts tolerances g8tzl which is why all manufacturers specify a minimum performance value. I have never seen an 8db differential between individual units of the same model in the same production run. Believe me, if there was that much swing in the performance coming off the line, "They" (whomever They are) would be trying to figure out why. Most of the time I see consistent performance that meets spec within a db.

Imagine the new customer having one radio that works great, one that works so-so, and one that is "deaf", when in fact all of them meet the spec. How do you fix that? You don't. Now you have a dissatisfied customer. The solution is to make all of them meet spec, and not much more. If the customer wants a hot receiver, he can pay for it. It becomes a value added commodity. That's problem number one.

Problem number two is selectivity. A rcvr has two jobs: receive the signal of interest, and reject all others. Sensitivity always comes at the cost of selectivity. The further down into the dirt a rcvr can hear, the more chances there are for it to get clobbered. Front ends, where the sensitivity is established, are broad banded. Selectivity occurs with front end filtering and in the IF chain after the first mix. Even window filters between the antenna and the preamp introduce some necessary loss. Some are tunable. Some are fixed. Very few front ends have filters with enough specificity to reject more than a few hundred kilohertz away. Most of the time they are megahertz wide. When a rx preamp is too sensitive, it can get swamped by seemingly low levels from other transmitters causing the rcvr to miss calls from units on channel. Drop the sensitivity just a few db, and that interfering signal no longer saturates the preamp. The calling unit can be received.

Again, if radios came off the line with that much difference between them, the manufacturer would be on it.
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

Maybe a 8dB difference is an extreme but even 3dB is too much. That's the difference between 50w and 100w on the TX side!!!

Motorola seems to think 3db is acceptable as they sometimes says the spec is 0.3uv (117dBm) but also quote a typical figure of 0.22uV (120dBm). They are basically saying that "on average" , you will get a radio which is 0.22uV but you might get one which is only 0.3uV....and at the same time you might get one that is, say, 0.14uV (124dBm)

My experience is that 70% of sets are all identical with average sensitivity....but 15% are hot and 15% are deaf.

If you own one of the hot 15% then you will be delighted and its the best radio you have ever owned.

If you own one of the deaf 15% then its the worst radio you have ever owned!!!!!

As a Motorola enthusiast, I only want one of the 15% of radios which are real hot!!! But I have a few of the 15% which are deaf!!
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Re: Whats the point of buying a 110w radio?

Post by Bill_G »

I don't see 3db among rcvrs off the same run. I rarely see more than a db on brand new equipment. I don't even see degradation over time. Short of failure, I see radios hit the same values over and over during PM's. So, I don't know where you are getting your numbers from. And I wouldn't call a radio a radio that meets spec deaf.

Again, this is that last mile stuff that you can't do anything about except to recognize you're in it, and really work the devil out of your set up. Whether you get it with power, with a preamp, with the antenna, your height, better line, lower your losses, or all of the above, depends on you. And I can guarantee that one size will not fit all - that you will find places that none of this will work.
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Re: Whats the point of buying a 110w radio?

Post by escomm »

g8tzl2004 wrote:Maybe a 8dB difference is an extreme but even 3dB is too much. That's the difference between 50w and 100w on the TX side!!!

Motorola seems to think 3db is acceptable as they sometimes says the spec is 0.3uv (117dBm) but also quote a typical figure of 0.22uV (120dBm). They are basically saying that "on average" , you will get a radio which is 0.22uV but you might get one which is only 0.3uV....and at the same time you might get one that is, say, 0.14uV (124dBm)

My experience is that 70% of sets are all identical with average sensitivity....but 15% are hot and 15% are deaf.

If you own one of the hot 15% then you will be delighted and its the best radio you have ever owned.

If you own one of the deaf 15% then its the worst radio you have ever owned!!!!!

As a Motorola enthusiast, I only want one of the 15% of radios which are real hot!!! But I have a few of the 15% which are deaf!!
Can you show me a manufacturer with better sensitivity specs and comparable selectivity specs? NO? Have you forgotten who we are talking about here? Come on....
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

Check out the RX-MTS vs XTS thread in the archives.

Note Karfields comments about MTS2000 RX sensitivity variability is 0.38 - 0.20uV !!!! Did he work at Plantation?

Also check out Keyguns comments about the Saber RX variabilty.

Also note all the comments about the XTS5000 which for some is deafer than an XTS3000 or significantly outperforms an XTS3000 for others !!!!

On narrowband, my XTS3000 leaves my XTS5000 standing.

I have about 10 UHF MTS2000's and sensitivity is all over the place..I have one hot one.

For 95% of users, sensitivity does not matter as they are not working in the last mile. But for hobbyists and commercial last milers, it does matter !!!
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escomm
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Re: Whats the point of buying a 110w radio?

Post by escomm »

How many of these threads dealt with brand new radios? Surely you can appreciate the need to PM equipment on a yearly basis

That said, I asked about other manufacturers

I see you are silent on the issue

The silence is deafening
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Re: Whats the point of buying a 110w radio?

Post by AL7OC »

IMHO, going from a 50 to 110 watt radio in and of itself is not a big improvement as far as improving coverage. That being said, if you buy a 3db improvement in output power, and couple it with low loss feed line, and a 3db gain antenna on both the transmitting and receiving side, now you have a 9 dB improvement, which is a big deal.

Given the choice between a 3db boost in output power or a 3 db gain antenna, go with the better antenna. The cost is less, and you will boost your receive path gain too.
Pierre

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Bill_G
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Re: Whats the point of buying a 110w radio?

Post by Bill_G »

Elements of this discussion remind me of the narrowband debate where people were absolutely certain they would lose range.
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Re: Whats the point of buying a 110w radio?

Post by MSS-Dave »

Another simple answer to the OP is because it is required by policy by some Municipal and Government agencies! If you don't offer it, you lose sales!

I am sure most if not all States in the USA have EMS and Mutual Aid policy in place. To buy under Government contract, you are supposed (my emphasis..) to buy approved radios. Florida used to state 100 watts on UHF for MedCom mobiles, now it is 90 watts wideband and 50 watts narrowband Minimum. Digital P25 drops to 40 watts. Low and High bands are 90 watts. Now, Florida is as flat as a pancake in most areas so policy probably reflects that. Like com501 says, If I am out in areas he works, I'm wanting every watt I can get out the box whatever band I am on.

Here's a link to Florida's EMS communications plan for example. They even spec minimum receiver performance.....

http://www.dms.myflorida.com/content/do ... dition.pdf
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Bill_G
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Re: Whats the point of buying a 110w radio?

Post by Bill_G »

Thx Dave!
g8tzl2004
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

In my experience, no other commercial radio manufacturer equals Motorola RX sensitivity...assuming you get lucky and it has a hot RX.

I recently tested a brand new boxed VHF CDM and it was deafer than my used Fleabay identical radio.

All my VHF MCS2000's have fantastic RX sensitivity - no other manufacturer gets close. I just got a "modern" Icom IC-F5061 and RX sensitivity is a BIG disappointment.

All my Euro Motorola GM350's have fantastic RX senstivity - the model lacks functionality but you can hear grass grow.

My Kenwood TK7180 has good RX but not quiet as good as my MCS2000 but better than my brand new CDM.

My Kenwood TK3180 equals my HT1250 but ONLY after realignment. The TK3180 is the only radio where front end realignment made any difference. It looks like Kenwood align for 0.25uV spot on and don't try to align for max senstivity...check out the service manual. On some of their radios, the SM states that you align for max sensitivity and then back off - I guess for IMD reasons???

My Vertex VX2200 is a big disappointment.

I'd be interested how EFJ, Relm and Harris radios perform RX wise compared to Motorola. I never realised that all these radios were made in the USA!!

However, my UHF MTS2000's and UHF MCS2000's are very variable sensitivity wise, as well as my Sabers. My UHF XTS5000's are deaf on narrow band but equal to my XTS3000 on wide spacing...go figure?

I have tried realigning the RX front end but the softpots are very broad and small changes don't have any real effect.

I have a theory that maybe MTS2000's have a problem with 2nd LO Xtals which have drifted. You can warp the ref osc back on freq (sometimes its up to 2KHz out) BUT how do you realign the 2nd LO Xtal?

With modern production techniques and DSP, surely every Moto radio can come off the production line with identical sensitivity...maybe they now do. I only hope that my XTL will be OK when I sort out the programming....but why why why did Motorola not supply all XTL radios with the pre-amp enabled as standard and if users did not want a sensitive RX they could just switch it off. Instead I will have to flash my XTL with another flashcode where the pre-amp option is provided.
Last edited by g8tzl2004 on Mon Feb 03, 2014 10:45 am, edited 1 time in total.
com501
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Re: Whats the point of buying a 110w radio?

Post by com501 »

g8tzl2004 wrote:.but why why why did Motorola not supply all XTL radios with the pre-amp enabled as standard and if users did not want a sensitive RX they could just switch it off.

Well, this is where you have to understand marketing AND engineering.

If I as a manufacturer, sell a radio with a feature enabled that could potentially cause problems in a high RF environment and create customer complaints, I shoot myself in the foot. On the other hand, if that feature is an option that the customer has to deliberately order, they then have the opportunity to understand what they are getting into by ordering it.

From a marketing standpoint, why should I GIVE away a feature when I can SELL it as an option and make more money?
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Re: Whats the point of buying a 110w radio?

Post by Bill_G »

g8tzl2004 wrote:In my experience, no other commercial radio manufacturer equals Motorola RX sensitivity...assuming you get lucky and it has a hot RX.

I recently tested a brand new boxed VHF CDM and it was deafer than my used Fleabay identical radio.

All my VHF MCS2000's have fantastic RX sensitivity - no other manufacturer gets close. I just got a "modern" Icom IC-F5061 and RX sensitivity is a BIG disappointment.

All my Euro Motorola GM350's have fantastic RX senstivity - the model lacks functionality but you can hear grass grow.

My Kenwood TK7180 has good RX but not quiet as good as my MCS2000 but better than my brand new CDM.

My Kenwood TK3180 equals my HT1250 by ONLY after realignment. The TK3180 is the only radio where front end realignment made any difference. It looks like Kenwood align for 0.25uV spot on and don't try to align for max senstivity...check out the service manual. On some of their radios, the SM states that you align for max sensitivity and then back off - I guess for IMD reasons???

My Vertex VX2200 is a big disappointment.

I'd be interested how EFJ, Relm and Harris radios perform RX wise compared to Motorola. I never realised that all these radios were made in the USA!!

However, my UHF MTS2000's and UHF MCS2000's are very variable senstivity wise, as well as my Sabers. My UHF XTS5000's are deaf on narrow band but equal to my XTS3000 on wide spacing...go figure?

I have tried realigning the RX front end but the softpots are very broad and small changes don't have any real effect.

I have a theory that maybe MTS2000's have a problem with 2nd LO Xtals which have drifted. You can warp the ref osc back on freq (sometimes its up to 2KHz out) BUT how do you realign the 2nd LO Xtal?

With modern production techniques and DSP, surely every Moto radio can come off the production line with identical sensitivity...maybe they now do. I only hope that my XTL will be OK when I sort out the programming....but why why why did Motorola not supply all XTL radios with the pre-amp enabled as standard and if users did not want a sensitive RX they could just switch it off. Instead I will have to flash my XTL with another flashcode where the pre-amp option is provided.
Tested how?
g8tzl2004
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

With the MCS2000 and GM350 , the "pre-amp" came as standard, I think.

Adding an external pre-amp to my VHF MCS2000 (at the radio end) does not improve the RX signal. The VHF MCS2000 has just the right amount of gain for max sensitivity.

The Euro GM350 is the same. Adding an external pre-amp does nothing. If you want to use the GM350 as a repeater, you need to short a couple of internal tabs which enables a 3dB attenuator!!!!

Can you do the same with an MCS2000 when its used as a repeater? Is there some internal tabs which enable an attenuator?

You have to be careful with some GM350's which have come out of a repeater as the 3dB attenuator is still enabled!!!

Maybe thats the problem with one of my UHF MCS2000's..but I can't find anything in the SM.

Are there a lot of issues with using an MCS2000 as a repeater because they are too sensitive and you get IMD issues?

With the XTL, its like the basic radio comes with the "attenuator" enabled and you have to pay to disable the attenuator...actually you switch on a 4dB pre-amp....BUT a basic XTL is 4dB deafer than an MCS2000 so all you are doing with an XTL is switching on a 4db pre-amp which allows equal RX performance to an MCS2000, I think.

I'd rather pay to switch on an attenuator to make my XTL deafer (if required for a repeater or base) rather than pay to enable a pre-amp to make it have equal RX performance to an MCS2000.

If you don't know about the XTL pre-amp and you compare an XTL without the pre-amp flashcode and an MCS2000, you are going to be disappointed with the basic XTL if you are a "last mile" user or enthusiast. This clearly will not apply to 95% of users who are always in strong and medium signal areas. If you are an XTL mobile user in the "last mile", it surely always makes more sense to enable the 4dB pre-amp before getting the base to increase its power to 110W?
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Re: Whats the point of buying a 110w radio?

Post by com501 »

Bill_G wrote: Tested how?

Hey! That's my question!

What service monitor and test procedure are you using for your comparisons?
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Re: Whats the point of buying a 110w radio?

Post by g8tzl2004 »

2023A with SINAD option.

But I prefer to use real world testing with the same identical antenna and a very very weak constant signal/repeater. Open SQ and listen for level of quieting and intelligibility between different radios. Simple but effective??

If a radio cannot hear the same identical signal as good as my MCS2000, I'm not happy!!!
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Re: Whats the point of buying a 110w radio?

Post by KE7JFF »

As someone who does search & rescue communcations in the mountains of the NW, I can tell you that extra 3.4 db increase in power helps...
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Re: Whats the point of buying a 110w radio?

Post by tsunami_australia »

110 / 50 would make a difference for us in the mountainous bush but regretfully Australia is limited to 25w mobile (/cry) and 50w repeater. However one VERY useful feature for us when using the radio for long overs is we can run the 110@25 and get near 100% duty cycle with no fans or other cooling required. ATM I'm running a GM300 45w @26w or so and it gets HOT still but with a fan it runs great so I'm looking to upgrade my Radius and regular MCS gear on UHF with 110w bricks. Most of the antennas over here would burn out at more than 35w I think anyway lol.
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Re: Whats the point of buying a 110w radio?

Post by desperado »

You are trying to answer a question with technical thought, logic, RF theory and the like. None of that applies. The reason that Moto sells 110 watt radios is there are customers that demand them. It goes back to the low band days of simplex operation without repeaters. All that stuff was high power. That and the feds swear by them. If you do any work for any government agency, they ALL run high power radios.
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Re: Whats the point of buying a 110w radio?

Post by escomm »

desperado wrote:You are trying to answer a question with technical thought, logic, RF theory and the like. None of that applies.
Just completely ignored the entire thread and went to hit reply, didn't you?
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Re: Whats the point of buying a 110w radio?

Post by com501 »

You mean a quarter kilowatt in my Expedition on 52.525 isn't normal?
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Re: Whats the point of buying a 110w radio?

Post by desperado »

escomm wrote:
desperado wrote:You are trying to answer a question with technical thought, logic, RF theory and the like. None of that applies.
Just completely ignored the entire thread and went to hit reply, didn't you?

Not really, I saw all the discussions that it's only 3 db more than a 50 watt and that the high power radios have preamps and what their gain is and lots of math. But I have sat there listening to firefighters wanting high power high bands, even with them working through a repeater that I know is right in their town and has good coverage. The ones that want the high power radios all give the same reason, and it boils down to they are convinced they need them because it's what they had before on low band. Typical statement is "we're firefighters and we need to be able to talk". Now your milage may vary. We don't sell high power radios to the city because they are on 800 trunked and have been long enough that their trucks don't even have high band any more or they realize it's a secondary radio. But the rural guys are pretty strong in the opinion that high power is the ONLY way to go. Even with a 5 site VHF simulcast system in their county that offers reasonable portable coverage in 90% of the county.


Why the feds run them is a mystery, but I would guess it's about the same thing.
But, we would be putting in 100 watt 800 trunked radios if they sold them... at least in fire trucks.
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Re: Whats the point of buying a 110w radio?

Post by escomm »

desperado wrote:
escomm wrote:
desperado wrote:You are trying to answer a question with technical thought, logic, RF theory and the like. None of that applies.
Just completely ignored the entire thread and went to hit reply, didn't you?

Not really, I saw all the discussions that it's only 3 db more than a 50 watt and that the high power radios have preamps and what their gain is and lots of math. But I have sat there listening to firefighters wanting high power high bands, even with them working through a repeater that I know is right in their town and has good coverage. The ones that want the high power radios all give the same reason, and it boils down to they are convinced they need them because it's what they had before on low band. Typical statement is "we're firefighters and we need to be able to talk". Now your milage may vary. We don't sell high power radios to the city because they are on 800 trunked and have been long enough that their trucks don't even have high band any more or they realize it's a secondary radio. But the rural guys are pretty strong in the opinion that high power is the ONLY way to go. Even with a 5 site VHF simulcast system in their county that offers reasonable portable coverage in 90% of the county.


Why the feds run them is a mystery, but I would guess it's about the same thing.
But, we would be putting in 100 watt 800 trunked radios if they sold them... at least in fire trucks.
Your rural guys are very fortunate to have a simulcast system. Your city guys are very fortunate to have an 800Mhz trunk system. Not everyone is as fortunate (or have the tax base) as your customers. Math is nice and all, except when you're on the fringe. I'm surprised this is still even part of the discussion. OP asked why people buy 110 watt radios and got his answer.

Seeing the number of second hand mid power XTL on fleabay that are obviously fed surplus I think it's safe to say that "not every fed buys a high power radio"
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Re: Whats the point of buying a 110w radio?

Post by SlimBob »

The point of buying a 110W radio...

1) Motorola got into a power war with somebody years ago and
2) someone became convinced that 110W was the only way to go.

3) 110W with a dipole/quarter-wave ("Kulrod", 0dBd) antenna is a 110W ERP
4) Equal in ERP to 50W with a +3dBd antenna gain (as provided by a 5/8ths wave antenna)
5) Without any of the vertical nulls.

6) You can talk car-to-car over roughly 30 miles simplex.
7) You amuse yourself by lighting up gas station lights at night or melting down lesser, cheaper quality antennas.

8 ) You have no responsibility for gas mileage impact.
9) Dispatch and the radio user have to hear each other, even if the user is out of the licensed area or down in a hole, or drove off the mountainside.

OTOH, when on lowband:

Repeaters? What's a repeater?
Last edited by SlimBob on Sun Feb 09, 2014 12:44 pm, edited 2 times in total.
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Re: Whats the point of buying a 110w radio?

Post by SlimBob »

com501 wrote:You mean a quarter kilowatt in my Expedition on 52.525 isn't normal?
If I may be nosy sir, what are you running that gives you 250W on lowband?

I've heard stories of a 250W mobile radio, but I have not been able to validate them.
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Re: Whats the point of buying a 110w radio?

Post by escomm »

SlimBob wrote: 4) Equal to 50W with a +3dB antenna gain (as provided by a 5/8ths wave antenna)
No
SlimBob wrote:OTOH, when on lowband:

Repeaters? What's a repeater?
A critical piece of life safety telecommunications equipment well utilized by the largest and possibly the most professional state police organization in the US??

~~~~~~~~~~~~~~~~~~~~~~

You're not trolling, are you? I can't tell.
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Re: Whats the point of buying a 110w radio?

Post by SlimBob »

escomm wrote: No
Seriously? You're going to argue that 50W into an antenna with 3dBd of gain isn't equivalent to 100W into a 0dBd antenna?
SlimBob wrote:OTOH, when on lowband: Repeaters? What's a repeater?
escomm wrote:A critical piece of life safety telecommunications equipment well utilized by the largest and possibly the most professional state police organization in the US??

~~~~~~~~~~~~~~~~~~~~~~

You're not trolling, are you? I can't tell.
The latter was sarcasm; few agencies have or use low-band repeaters. IIRC Part 90 didn't even allow such for quite some time. A repeater isn't a critical piece of gear, otherwise you would argue that the system used by the State of Alabama to support ALDPS / Troopers isn't a life-safety system. (The aforementioned system uses remote bases back-hauled over leased lines to a central dispatch point at Selma, AL.) But the nature of DPS -- and the infrequency with with Troopers deal with each other or management -- largely removes the need of repeating all radio traffic heard on the base station input.
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Re: Whats the point of buying a 110w radio?

Post by escomm »

SlimBob wrote: Seriously? You're going to argue that 50W into an antenna with 3dBd of gain isn't equivalent to 100W into a 0dBd antenna?
Sure. So will the receive antenna at 5000 feet AGL with the transmit antenna at sea level. At this point I'll submit there is no argument to make and if you want to assert equivalency then you will need to substantiate your argument. When (and if) you're able to change the laws of physics, by all means I would be willing to make another consideration.
SlimBob wrote: The latter was sarcasm; few agencies have or use low-band repeaters. IIRC Part 90 didn't even allow such for quite some time. A repeater isn't a critical piece of gear, otherwise you would argue that the system used by the State of Alabama to support ALDPS / Troopers isn't a life-safety system. (The aforementioned system uses remote bases back-hauled over leased lines to a central dispatch point at Selma, AL.) But the nature of DPS -- and the infrequency with with Troopers deal with each other or management -- largely removes the need of repeating all radio traffic heard on the base station input.
How Alabama elects to support their sworn officers is up to Alabama. That said, Alabama (nor any other state police agency in the US) does not have the challenging coverage requirements for a statewide system like California does, except perhaps Alaska? And in watching a certain "reality" TV show on Discovery, I know that Alaska is not without its own coverage holes where law enforcement officers find themselves on a regular basis.

Alabama doesn't have anywhere near the capacity requirements California does, either. I imagine Alabama would have quite an interesting day if a giant brick fell on Selma. Centralized dispatch is nice and all, but this is 2014 and operational redundancy and just in case redundancy are two separate concepts. I'll concede this is neither here nor there at this point and likely to derail the thread a bit, but who cares, productive discussion is productive discussion.

Edit: And whoa, leased lines.... you're suggesting relying on the phone company for a mission critical radio system?!?! With a straight face?! :lol:
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Re: Whats the point of buying a 110w radio?

Post by desperado »

They been relying on leased lines for years, hell the original civil defense sirens in Newark Ohio were on leased lines for a long time, not to mention their radio system.

And am surprised that the Ohio, Michigan, and I believe Illinois have state wide systems. Of course the Ohio system is 3.5 Smart Net, and is LONG in the tooth. They are working on going to 7.13 at this point. The site hardware is in most of the sites. Not sure how many are turned up yet. I know other than One site in Columbus and the Cleveland area, it's not under contracted MSS support yet. The site in Cbus under support is 7.9 and not part of the new roll out.
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Re: Whats the point of buying a 110w radio?

Post by KitN1MCC »

we have 5 Low band repeaters to Cover 17 towns in south west Ct. split in two the East side has two and the west has 3.

Both sides all have the same RX frequency that is voted. and brought back to Dispatch

also the system has a type of fail soft if the tie back to the voter fails each repeater can operate on its own
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Re: Whats the point of buying a 110w radio?

Post by Solo »

To answer the original question, it's because a lot of the world is outside of 50W mobile radio range, thanks to distance or terrain.

Look at Nevada, where I live. Outside of the two metropolitan areas (Las Vegas and Reno, which are 300 miles apart), it's a lot of Big Empty Nothing. Unlike the Midwestern US, it's not flat -- we have mountains and valleys. I've had times where a repeater 20 miles away was out of range, while being able to work a repeater 250 miles away in Utah at the same time.

I used to have to aim my car a particular direction and stop at a handful of specific points in the highway in order to hit one of the three repeaters I often needed to reach, using the best antenna I could get. Going to 50W meant that I could stop anywhere in the area and hit it. Going to 100W meant that if I could hear them, I could reach them, without having to stop, all on the same antenna.
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Re: Whats the point of buying a 110w radio?

Post by SlimBob »

So the final answer is ERP and antenna pattern. That's why you buy a 110W radio. Coverage, plain and simple.
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Re: Whats the point of buying a 110w radio?

Post by Birken Vogt »

SlimBob wrote:So the final answer is ERP and antenna pattern. That's why you buy a 110W radio. Coverage, plain and simple.
While that is a valid point for some situations, I think the other answer (marketing) is probably correct for many more of the cases where they have been sold. I can only think personally of a few instances that I have thought that a 110 watt radio was a worthwhile investment of money, in fact, we use and sell more 35 watt radios than anything. But it depends on the application, of course. Most of the time they are bought because the purchaser "wants them" and for no technical reason.
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