Batboard

I'm using a VHF Syntor X9000 as a base station at the shop now. Common sense be hanged, I want to see how far out I can crank up the PA output
on it. I've already got a very clean 150 watts out of it and it doesn't even seem to care, and I've heard that 225 or maybe even 250 watts is possible
out of an X9000 with a few simple changes and maybe a couple minor mods.

I'd like to find out how this is usually done. I've got some hefty power supplies available to run the thing once the mods are done. I'm getting the 150
watts output at 14.8 volts on the big red lead, all that Astron 35 amp variable PS will give me. Current draw is about 28 amps and at this moment
the current limiter is set just outside the limit I'm running at now.

Cooling isn't a problem. Fans are cheap and this is a base station setup.


Elroy

Your problem may be the driver stages, not giving you the mid drive you are looking for.

M9583 is only a 25 watt driver, and while the M1104's in parallel can "deliver more than 20% of the radio's rated capacity", you may have to increase your drive to see more than that.

You can try and feed more than 1.5 watts from the IPA to the first amplifier and see where that gets you, but this can lead quickly to the place where you find how much the components cost to replace unless you are like some who have a snot load of these just sitting around holding the floor down.

Also, I would not try " more than 20% " through the RF sense stages as you may find the rating of these components Really quick.

Have at it, melt some wire, burn a hole through some PCB, let the brown out and let us know your outcome.

CoM

I know there are some people running them at 225 watts or better, reliably. And X9000s are cheap these days. I'm not going to cry if I roast a PA stage in
the quest for insane power levels. I can replace the drawer unit in minutes if need be. Running a slight overvoltage at 14.8 volts DC, I'm getting a clean 150
watts out of the radio already, measured via a recently calibrated HP wattmeter and calibrated, documented high power attenuators. (I can measure up to a kilowatt
with high accuracy with this system.)


I've done some tests on heat buildup on the X9000 during long transmissions at 150 watts. What's really amazing to me is that the radio
just doesn't seem to get more than barely warm no matter how long it transmits. It makes me wonder why Spectra high power radios get
so much hotter when the total heatsink area seems to be not all that much different.


Elroy

Elroy Jetson wrote:I know there are some people running them at 225 watts or better, reliably. And X9000s are cheap these days. I'm not going to cry if I roast a PA stage in
the quest for insane power levels. I can replace the drawer unit in minutes if need be. Running a slight overvoltage at 14.8 volts DC, I'm getting a clean 150
watts out of the radio already, measured via a recently calibrated HP wattmeter and calibrated, documented high power attenuators. (I can measure up to a kilowatt
with high accuracy with this system.)


I've done some tests on heat buildup on the X9000 during long transmissions at 150 watts. What's really amazing to me is that the radio
just doesn't seem to get more than barely warm no matter how long it transmits. It makes me wonder why Spectra high power radios get
so much hotter when the total heatsink area seems to be not all that much different.


Elroy

Is this on a commercial system? Are you licensed for mobile/base operations at those power levels?

Is this an amateur setup? Is 225w necessary as the minimum amount of power required to communicate?

Not a flame, but honest questions. Ask yourself if this is a responsible thing to do legally.

Please understand that I'm a trained professional radio technician engaged in the business full time. I operate within all FCC regulations on frequencies that
I am authorized to operate on, and only those. I'm also an amateur radio operator and some of the channels in the radio are within the 2 meter band,
for that purpose. Again, all FCC regulations are complied with.

So let's stick to the technical side of the question, shall we? The legal aspects are entirely under control.

My "need" or "desire" to perform such modifications, and my motivation for doing so, is not any matter of concern to you. So please avoid comments on it
as it's entirely outside the range of this discussion, AND such comments are unwelcome and will be ignored.

I'm still looking for information on how high power modifications are USUALLY performed on a VHF X9000 transmitter. I'd much rather follow proven
modifications than try to reinvent the wheel and come up with my own that may or may not work as intended.

Elroy Jetson wrote:Please understand that I'm a trained professional radio technician engaged in the business full time. I operate within all FCC regulations on frequencies that I am authorized to operate on, and only those. I'm also an amateur radio operator and some of the channels in the radio are within the 2 meter band, for that purpose. Again, all FCC regulations are complied with.

So let's stick to the technical side of the question, shall we? The legal aspects are entirely under control.

My "need" or "desire" to perform such modifications, and my motivation for doing so, is not any matter of concern to you. So please avoid comments on it as it's entirely outside the range of this discussion, AND such comments are unwelcome and will be ignored.

I think given what you're asking, you're going to have to expect such questions. It's a little bit like asking for tips on installing a jet engine into a Cessna.

However, some dusty bit of knowledge from my ham test many years ago says that technician licensees are limited to something like 200w PEP?

Elroy Jetson wrote:I'm still looking for information on how high power modifications are USUALLY performed on a VHF X9000 transmitter. I'd much rather follow proven modifications than try to reinvent the wheel and come up with my own that may or may not work as intended.

Well, driving an RF power amp up to 250% of capacity doesn't normally have anything "usual" about it. I'm sure you know, as a radio tech, driving components that far outside their rated capacity can cause all sorts of problems, not only limited to greatly decreased efficiency leading to increased waste heat generation, but also nasties like spurious emissions.

If you absolutely positutely have to have that much power, why not dial back the power on the radio and add a purpose-built power amplifier into the mix?

akardam wrote:

Elroy Jetson wrote:Please understand that I'm a trained professional radio technician engaged in the business full time. I operate within all FCC regulations on frequencies that I am authorized to operate on, and only those. I'm also an amateur radio operator and some of the channels in the radio are within the 2 meter band, for that purpose. Again, all FCC regulations are complied with.

So let's stick to the technical side of the question, shall we? The legal aspects are entirely under control.

My "need" or "desire" to perform such modifications, and my motivation for doing so, is not any matter of concern to you. So please avoid comments on it as it's entirely outside the range of this discussion, AND such comments are unwelcome and will be ignored.

I think given what you're asking, you're going to have to expect such questions. It's a little bit like asking for tips on installing a jet engine into a Cessna.

However, some dusty bit of knowledge from my ham test many years ago says that technician licensees are limited to something like 200w PEP?

Elroy Jetson wrote:I'm still looking for information on how high power modifications are USUALLY performed on a VHF X9000 transmitter. I'd much rather follow proven modifications than try to reinvent the wheel and come up with my own that may or may not work as intended.

Well, driving an RF power amp up to 250% of capacity doesn't normally have anything "usual" about it. I'm sure you know, as a radio tech, driving components that far outside their rated capacity can cause all sorts of problems, not only limited to greatly decreased efficiency leading to increased waste heat generation, but also nasties like spurious emissions.

If you absolutely positutely have to have that much power, why not dial back the power on the radio and add a purpose-built power amplifier into the mix?

Elroy, I too am a trained radio technician. Actually I'm a Senior Systems Technician, CET w/ USMSS endorsement, MWFE, ad. infinatum. for one of the oldest MSS's in the world. I only mention it since you seem to be interested in throwing around qualifications.

If I have a high power application, as a trained radio technician, I use the correct equipment to get the desired power level, not run things out of specifications. We have one base station that has a 500 watt transmit power requirement. We don't use a bunch of stuff turned up way past it's specs, we use a TPL 500W continuous-duty RF amplifier that's designed for the task.

MODS, PLEASE UNDERSTAND THE FOLLOWING IS NOT INTENDED AS A FLAME:

As a trained radio technician, you seem to spend a lot of time asking questions out here that most trained radio technicians would hopefully know, even at an entry-level. You also seem to do a lot of things that most trained radio technicians would never do. Don't get on my case about your "qualifications", and don't pull the "I know what I'm doing" nonsense because 99.9% of the people here wouldn't do what you're doing, or talking about doing. It's just plain BAD PRACTICE. A "trained radio technician" would know better.

akardam: Techs are licensed for 1500W max TX PO except where limited by location or band.

What I do with my own personal equipment is not necessarily the same thing I'd do with a customer's equipment. If a customer has a 110 watt rated
mobile radio, I'll tune to 110 watts and no more. I'll tune down if his range and performance requirements allow it.

But for my own stuff, particularly when it was obtained at minimal cost, sometimes even free, I don't have the slightest objection to doing a little experimentation
and modification, at least for use within an amateur band. "How far out will this sucker really go?" is a question that has crossed my mind more than a few times in
my life, and sometimes I will start messing with the hardware to find out. If I smoke it, well, I'll see where the first weak point is. And any that follow. Very
instructive, and really, NOT a big deal to me.

I've asked a few questions here and there that some more experienced technicians may just know off the tops of their heads, but I've been a hobbyist for most of
the years I've been into radio rather than a "real" professional technician, which is a fairly new career development for me. As a result, I don't actually have a
lot of bench time experience with a lot of older radio platforms, such as Maxtracs, Spectras, Maratracs, etc... There are tricks to them that I've just never picked
up on due to lack of prior opportunity. I certainly couldn't afford to buy new radios just to tear them apart and learn how to fix them, and wasn't working for a
service shop at the time, either. So my opportunities to get very familiar with those older products were actually kind of limited.

You know, I've never advertised myself as a master technician. I do all right but there's a great deal I don't know. And the more I learn, the more I realize
that there is yet to learn.

Today, the lion's share of my service activities are with Icom and Kenwood radios. They're the main lines that my shop deals in. Some Radius line radios as well,
but not very many of them come in need of repair. If they do, they're usually heavily water damaged and are replacement candidates.

At least over about the past three or four years I've picked up a lot of knowledge about a lot of newer radios. Not just Motorolas, but I've learned almost more than
I ever wanted to about various GE/whatever-they're-called-this-week radios, too. I probably know some of those models as well as I ever learned a Saber or an MX,
and I did learn those inside and out. I think I could draw their schematics from memory!

I'd like to be as diplomatic about this as possible, but frankly I don't have any need for anyone to assume the role of "ham cop" or "radio policeman" for me. I'm
quite responsible about such things and you don't have to worry about it.


Elroy

OK, if we're all done with the 'I'm badder than you' stuff, here is my answer to the question.

Best I have gotten before things start flaming was around 165watts out. What went was some components in the harmonic filter section, followed shortly by a failure in the power control circuit. That is where I stopped, as I had to repair the radio anyway. This may have been a problem with the radio in the first place.

I try to stay below 100watts as my fillings ache.

Best of luck, and keep us posted on your flameage.

I guess I'm just perfectly happy with a measly 150 watts. I'm not worried about actually doing the higher power mods, but I'm a bit curious as to how
it would usually be done. The coverage area I'm getting off this setup is already pretty darned impressive. Simplex range, base to mobile radio, is close
to 20 miles at just short of full quieting. That's more than half the county and adequate for all my existing needs, with ease.

There's literally not one 2 meter amateur repeater in the county that it doesn't get into at full quieting. Not bad, considering this county is about 78 miles long.

I'm just going to leave it as is. Why mess with success? Even I don't do that.

Elroy

So, I guess my TPL 50watt in, 350watt out UHF amp in my truck (continuous duty) is a bit much on 440 within 10 miles of the PAVEPAWS??

I'd say you're probably making full quieting on them even when you can't hear their signal at all.


Elroy

Tracking space junk is overrated..... !!

Night!

com501 wrote:So, I guess my TPL 50watt in, 350watt out UHF amp in my truck (continuous duty) is a bit much on 440 within 10 miles of the PAVEPAWS??

Nah, only transmitters listed in the Repeater Directory can bother PAVEPAWS.