Batboard

We are ordering a new ambulance, I am debating what radio to go with. We currently have cdm1250's but they arn't cutting it. They are confusing people and at times, are not making it to disp like our syntors did. Our syntors were 110w and our cdm's are 50w. Should I go with the pm1500, cdm1250 or a kenwood? No matter what, I need 2 of them.

I'd go with the PM1500. It's available in a 110w version, plus you'll be better positioned for future upgrades. The DSP will also improve the overall audio quality.

-Mike

mikegilbert wrote:The DSP will also improve the overall audio quality.

No

What about a Kenwood?

are you guys licensed to use a 110w radio? what kind of system are you using? maybe your system needs updating and it's not the mobile radios? it could be as simple as placement of the antennae?

yes, we are licensed for 100w. Our system does need updating but they will not update it.

also- what vhf antenna would you suggest?

The last time I looked, the PM-1500 only came in a trunk mount.

it is a good radio for VHF and UHF. So far don't think they
have come out with any other bands. The PM's come with
the M5 version control head which I rather like. It seems
much more user friendly and has a few more soft program
things you can do with it.

The radio can have up to 4 control heads connected to it.

You program the radio through the control head mic
connector. This means another programming cable, but
it also fits the new O5 control heads on the XTL series radios.
The new cable is USB so it should fit most of the newer
computers now out there.

The RSS is used for both the PM series and the XTL series mobiles.

Jim

escomm wrote:

mikegilbert wrote:The DSP will also improve the overall audio quality.

No

Lol.. I like that reply, short and to the point, and I agree completely.

escomm wrote:

mikegilbert wrote:The DSP will also improve the overall audio quality.

No

Care to elaborate, dealer man?

my only issue is the price. We need two of them for the ambulance because the radio in the cab must also be able to hear our disp channel and the radio in the back may have to be on another channel @ the same time.

mikegilbert wrote:

escomm wrote:

mikegilbert wrote:The DSP will also improve the overall audio quality.

No

Care to elaborate, dealer man?

The DSP will degrade analog transmission quality because they are needlessly routed through the DSP. Whoever says that digital two-way radio audio sounds better than analog needs their ears checked

escomm wrote:
The DSP will degrade analog transmission quality because they are needlessly routed through the DSP. Whoever says that digital two-way radio audio sounds better than analog needs their ears checked

I will second that.
________________

Adidtionaly, DSP adds some distortion that makes it difacult to hear the audio. In the past Motorola radios had very low distortion in both the receiver and transmitters, but latley ..NOT...

are you on a repeater or simplex? and where is the base antennae located and what type is it? on the rigs if you use the cdm's with a 3db gain antennae you will be around the equivalent to 100w with the standard 16" antennae. but alot still depends on the base, it's output, it's height and placement, the terrain?

And I'll third it.

I've got a trio of XTS3000's and an XTS2500 here that I'd much rather communicate in analog than in digital if I had to. Not to say I don't like them, but I'll take a pair of used HT1000's any day for plain, "un-fooled around with" (think florida orange juice commercial) analog.

HLA wrote:are you on a repeater or simplex? and where is the base antennae located and what type is it? on the rigs if you use the cdm's with a 3db gain antennae you will be around the equivalent to 100w with the standard 16" antennae. but alot still depends on the base, it's output, it's height and placement, the terrain?

We are simplex to cover 15-20 miles. Doesn't work out well at all! Our base antenna is in the middle of our borough. It is a 60' tower so it's probably 40' high. Our PD repeater antenna at at 60. Our base's output is probably 110. I like the antenna idea. If you give me a link to a good one, we may go with that. I am still looking for a good antenna for the new rig. Thanks.

also- I am still debating of my choices
choice 1: have 2 pm1500's (1 in cab, 1 in rear). very expensive.
choice 2: have pm1500 in front, cdm in back. would solve the power issue in the front, but will have two different radios on the rig.
choice 3: have 2 cdm1250's. Will match other rigs, however, we will have difficulty reaching headquarters without a repeater.

I hate the fact that I will have to buy 2 1,200 mobile radios.

Jim202 wrote:
The radio can have up to 4 control heads connected to it.



The RSS is used
Jim

This radio doesn't do multiple control heads I thought. At least it wasn't released yet.

20 mile radius should be just fine with a cdm. one thing i'd do first is see if you can get 10 or 15 more feet of height on the base antennae. that difference will be like night and day for distance. if the base is putting out 100watts, what is the gain on the base antennae? is it a 10db gain? and if height will do on the rig, i'd put a 3db gain antennae on the top center of the rigs and use a cdm.

HLA wrote:
< on the rig, i'd put a 3db gain antennae on the top center of the rigs and use a cdm.

I wonder if he has a GOOD ground plane for the antenna. Most "rig's" are fiberglass roofs and the rig manufactures do not put any ground plane in the roof. Well, sometimes just a little piece of window screen.. That does not work well at all.

maxrad makes a 3db gain antennae that don't require a ground plane.

escomm wrote:

mikegilbert wrote:

escomm wrote: No

Care to elaborate, dealer man?

The DSP will degrade analog transmission quality because they are needlessly routed through the DSP. Whoever says that digital two-way radio audio sounds better than analog needs their ears checked

In addition, the DSP also contains no code to clean up the analog audio anyway, unlike HF rigs (ham, military and commercial) that contain DSPs programmed to do that.

A gain antenna will help some, but don't expect it to be a drastic change. Personally I think you should stay with the CDM's and spend your money on getting that base station antenna in the air a little more, thats where you will notice the coverage change. Also if you only need to talk to dispatch your base is fine, but if you need to talk to other units out in the field consider getting a repeater. Think elevation, power is not everything.

we also need to talk to our field units, but we do not have the money for a repeater.

I look at it this way, you are going simplex all over the place right now , yes? You can add more power to the first part of the equation, but if your power is barely getting you to your most central point, and if both of your units are in miserable places of reception, no power in the world will solve that issue...(at least not what you can provide in a mobile basis).

I would say get a Kenwood TKR (you did say money was tight, and if you can afford one of these multi-headed monster mobiles that have been thrown out there you can definately afford a TKR), a good hardline install, and a gain antenna(e) and put gain antenna on your mobiles. Why throw power at a problem when common sense and good infrastructure can solve it?

What exactly does the tkr do? What is it?

It's a repeater, TKR-750 (VHF) / TKR-850 (UHF). Quite cheap at I think about $1500 list, but an excellent piece of kit.

yea. We just need to money for the licenses and duplexer and antenna now!

I have decided to go with two cdm 1250's w/ dtmf mic's. I am just looking for a good antenna now. I prefer 3db but I will only have about 12 " of roof clearance.

What about a power amplifier?

Expect to pay no less than around $600 for a high power VHF mobile amp.

I appreciate all the help. The best solution is the repeater, however, we do not have the money right now to pay for it.

Every ambulance I worked on, the roof was always double or tripply ply aluminum. (At least the boxes, not the vans)

Sprinter vans have a metal roof, except for that fibreglass fairing towards the rear.