Motorola PX series in Amateur service.

[KA5PIU]

Hello.

Everyone has seen them, the bulky pack sets by Motorola.
One stands out, the PX series.
What is inside is a Motorola MX series talkie and amplifier with power levels of up to 15 watts.
Some were converted to Smartnet by way of replacing the radio inside with an STX and the advanced HHCU.
Point being is that it is a very simple matter to remove the talkie and put in whatever you want, and they are cheap.
I would look for the PX-500 if given a choice.

[kb2crk]

what is a px-500?
motorola does not use hyphens or spaces in their models.
are you talking about the antique pt500 series?
or are you just talking shit again?

[KA5PIU]

Hello.

This is a bit later than the PT series but the same form factor.
The MX was the talkie, the PX was the lunchbox.

[kb2crk]

Hello.

This is a bit later than the PT series but the same form factor.
The MX was the talkie, the PX was the lunchbox.

why would anyone want such a thing as information on it is severely lacking?
parts availability has got to be rough too due to the age of the units.
it would be easier and cheaper in the long run to buy a more modern ht.
you can get a ht750 for less than a hundred bucks and parts and programming are redily available.
in a search of the interwebz i found just one reference to the px500 and it was a link to the repeater builder website.
plenty of info on the MX but nothing more than a passing mention of the px

[n2ize]

why would anyone want such a thing as information on it is severely lacking?
parts availability has got to be rough too due to the age of the units.
it would be easier and cheaper in the long run to buy a more modern ht.
you can get a ht750 for less than a hundred bucks and parts and programming are redily available.
in a search of the interwebz i found just one reference to the px500 and it was a link to the repeater builder website.
plenty of info on the MX but nothing more than a passing mention of the px

It's the challenge of doing it. Thats what ham radio is al about.

[kb2crk]

a challenge is building from scratch. using something that was not popular enough to get a little info on is something different.

[KA5PIU]

Hello.

You are missing the point.
Inside the PX300/PX400/PX500 is a MX300 talkie.
Remove the talkie and put whatever you want in it.
Radio B+ is 7.5 volts, battery B+ is 14 volts.
The PX500 for 800 MHz has a 15 watt RF amplifier that works fine from 50 to 450 MHz.
http://www.batlabs.com/ptpx300.html
You see them at hamfests around here quite a bit.

[kb2crk]

Hello.

You are missing the point.
Inside the PX300/PX400/PX500 is a MX300 talkie.
Remove the talkie and put whatever you want in it.
Radio B+ is 7.5 volts, battery B+ is 14 volts.
The PX500 for 800 MHz has a 15 watt RF amplifier that works fine from 50 to 450 MHz.
http://www.batlabs.com/ptpx300.html
You see them at hamfests around here quite a bit.

inside are the boards of a mx talkie, not the talkie itself. the lunch box was around for years but i have not seen one at a hamfest in 20 years. if you want to play with stuff like that it is your choice but with no info on the lunchbox i would shy away. there are to many other good options, and that would be motorola options. of course another thing to think about is the crystal control. most of these were not synthesized.

[kb2crk]

http://cgi.ebay.com/Motorola-PT500-VHF-Radio-/220707144194?pt=2_Way_Radios_FRS&hash=item33632bc202#ht_500wt_1156
http://cgi.ebay.com/MOTOROLA-PT300-HANDIE-TALKIE-FM-PORTABLE-RADIO-/270665427132?pt=2_Way_Radios_FRS&hash=item3f04eaa8bc#ht_500wt_922

here are a couple listings on ebay for the pt series. there was a battery case for a px 300 listed but it was an empty case.
for the price of the pt300 i can get a HT750 in working condition and it would not need crystals....
but to each his own rudy.

[NQ6U]

Paul, since you seem to know a lot about Motorola radios, is there a mobile unit that can be had for cheap (less than a Icom or Yaesu unit, that is) which can be made to work on the 70cm ham band?

[kb2crk]

Paul, since you seem to know a lot about Motorola radios, is there a mobile unit that can be had for cheap (less than a Icom or Yaesu unit, that is) which can be made to work on the 70cm ham band?

carl
i currently use a couple of maxtrac radios on 70cm. i bought my first one off ebay for 25 after shipping. i was an eight channel radio that i have since changed to a 32 channel radio. (Board swap)
i have a few other maxtracs set up for 70cm and they are 32 channel units now also. these were bought as a parts radio lot of ebay for .99 cents and 40 dollars shipping with a ton of other stuff.
if you look around you can find a 32 channel 40 watt maxtrac for less than 50 bucks. the trick is in the programing. software belongs to motorola and they do not like to share. there are quite a few hams around that use these radios and might have access. the maxtracs should be getting cheaper as we get closer to full implementation of the narrow band requirement in 2013. so should the maratracs which are remote mount units and again the uhf model will work in the 440 band.

[n2ize]

a challenge is building from scratch. using something that was not popular enough to get a little info on is something different.

Building from scratch is not the only challenging thing in ham radio. It is also very challenging to find an old radio and get it restored and back on the air again. It often involves ingenuity, such as redesigning parts of the circuit using more modern and efficient components or using modern components to perform the function of those parts which may be obsolete or hard to find. If a particular radio was relatively unpopular and has little or no documentation it gets even more challenging as it requires more ingenuity on the part of the Op to figure out how it all works, what does what, and how to make it work again. Just look at those who find old ,military gear and get it back on the air, either in its original form or in some modified form.

[kb2crk]

Hello.

Everyone has seen them, the bulky pack sets by Motorola.
One stands out, the PX series.
What is inside is a Motorola MX series talkie and amplifier with power levels of up to 15 watts.
Some were converted to Smartnet by way of replacing the radio inside with an STX and the advanced HHCU.
Point being is that it is a very simple matter to remove the talkie and put in whatever you want, and they are cheap.
I would look for the PX-500 if given a choice.


Building from scratch is not the only challenging thing in ham radio. It is also very challenging to find an old radio and get it restored and back on the air again. It often involves ingenuity, such as redesigning parts of the circuit using more modern and efficient components or using modern components to perform the function of those parts which may be obsolete or hard to find. If a particular radio was relatively unpopular and has little or no documentation it gets even more challenging as it requires more ingenuity on the part of the Op to figure out how it all works, what does what, and how to make it work again. Just look at those who find old ,military gear and get it back on the air, either in its original form or in some modified form.

you make some good points but that is not the issue i have with rudy's statement.
as you can see from rudy's quote above yours he states that these are easy to find, cheap, and all you have to do is pull one walkie out and pop another one in.
problem one is they are not that common. problem two is there is almost no info on the px500 and how to align its amplifier to the different bands rudy states it can be used on.
most of them are crystal controlled and those that are programmable require you to write to the eprom.
so not simple and not cheap as rudy states.

[KA5PIU]

Hello.

First off, since the entire radio section is being removed there is no issue whatsoever in alignment, remember that this is an 800 MHz radio and trunking at that.
Alignment of an amplifier module? what is there to align? it is a an RF module intended for 800 and 900 MHz.
If one places 1.8 watts of RF at 50 MHz in we get 15 watts out.
If we place 2.3 watts at 450 in we get 15 watts out.
So I crank the gain of the talkie to conform to these figures, not the amplifier.
There is little in the way of filtering in the amplifier section and it was never intended to operate at anything but 800 MHz so the talkie mush have a pure signal to begin with.
And the things are becoming quite common, this was the pack set mounted on utility equipment.
Both Bexar County and San Antonio have shut down all Motorola Smartnet operation and the utility has gone to a Motorola Harmony 800 MHz system.
So 800 MHz equipment is now plentiful in surplus.
Again, I am not making use of the radios, just parts and pieces like power supplies and speakers and amplifiers.
And if you can not find 800 MHz Motorola trunking equipment you are not looking, everyone is going digital P25 so the analog trunking is surplus everywhere.

[kb2crk]

800 mhz trunking equipment is a dime a dozen.
it is the pack sets that seem to only be easily accessible in your world.

[KA5PIU]

800 mhz trunking equipment is a dime a dozen.
it is the pack sets that seem to only be easily accessible in your world.

Hello.

I have provided the information on what is inside to the point to where if somebody has a PX500 in 800 MHz they have an idea of what to do with it.
If you can not find one that is your problem but 800 MHz equipment is easy to find.
Remember this is about reuse of equipment that some might otherwise overlook, such as desk sets, ask yourself if that may be a good home for a mobile.
Ignore the RF amplifier if you feel you can not do anything with it, run the radio direct.
Look at it as a cheap source of parts, nothing more.

[kb2crk]

what you have provided is a pile of BS. even the batboard has almost nothing on the px500. there are none for sale on the web and information is lacking. the links you provided show how little is available on the equipment you say is so easily found. all of your posts seem to run this route rudy. someone calls you on it and then you provide links that dont show a thing. the pt series of radios is still over priced so cheap parts does not fly either.
as for the 800 mhz crap i have 2 maxtrac LS radios in the garage that have donated their 16 pin logic boards to vhf and uhf radios. i got those as freebies when i bought two gm300 remote kits and some vhf p50's as a lot. i bought a 800mhz spectra for 7 bucks from suwannee ga and sold it on greedbay for 70. 800 mhz radios are cheap and plentiful but the packsets seem to be rare as hell. so as i said rudy, they seem to be plentiful in your world along with the apu's for your non flying bell helicopters.

[kb2crk]

http://www.1stopretroshop.com/walkie-talkies-radios/portable-transceiver-radio-with-case.htm

another link to a px300. still have yet to find the readily available px500's

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120632603028&nma=true&rt=nc&si=mhjeRYnilUayHjBgJEFi6MmFVkg%253D#ht_500wt_1156

and a late model px300s on ebay... late model being the 80's this was one of the programmable ones


http://cidaderiodejaneiro.olx.com.br/radio-motorola-px300-s-iid-58256266

and a couple in brasil but still no px500 to be seen.

[KA5PIU]

Hello.

Except for the amplifier the PX300 and PX500 are the same radio.
Since you are having so much concern over the amp may I suggest you stick with the PX300?
And, if you read the original post, I said I got the last 2 PX300s, thus it was assumed that it was clear that there was, oh, lets say, TWO of the things?
The post deals with trunking in general and the fact that radios can be had for little or nothing.
As an absolute policy I do not sell Motorola 2 way radios or software.
Once I am complete there is nothing but the Motorola name on the box.
The Packset has a VX-7R inside.
For the TH-f6a I use the convertacom from an old Handi-com with a bracket that the belt clip slides on.
But my normal carry radio is a VX-3r and a large Thales talkie nearby.
My goal in all of this is to maintain communications, not play whacker.
If you can find a packset, excellent, but that is your quest and clearly not my problem.
The only fully functional Motorola around here are the Sabres and 2 cellphones.
Plus 2 Syncoms and a Compa-base with a pair of coverta-coms in place of that Mocom 70 like radio, a dual band base if you will.
Everything I got cheap or free locally.
Find a community upgrading to digital or trunking and get in good, nagging to me will do you no good as I will not help you.

[kb2crk]

Hello.

Except for the amplifier the PX300 and PX500 are the same radio.
Since you are having so much concern over the amp may I suggest you stick with the PX300?
And, if you read the original post, I said I got the last 2 PX300s, thus it was assumed that it was clear that there was, oh, lets say, TWO of the things?
The post deals with trunking in general and the fact that radios can be had for little or nothing.
As an absolute policy I do not sell Motorola 2 way radios or software.
Once I am complete there is nothing but the Motorola name on the box.
The Packset has a VX-7R inside.
For the TH-f6a I use the convertacom from an old Handi-com with a bracket that the belt clip slides on.
But my normal carry radio is a VX-3r and a large Thales talkie nearby.
My goal in all of this is to maintain communications, not play whacker.
If you can find a packset, excellent, but that is your quest and clearly not my problem.
The only fully functional Motorola around here are the Sabres and 2 cellphones.
Plus 2 Syncoms and a Compa-base with a pair of coverta-coms in place of that Mocom 70 like radio, a dual band base if you will.
Everything I got cheap or free locally.
Find a community upgrading to digital or trunking and get in good, nagging to me will do you no good as I will not help you.

the lowest price i saw was 75 dollars. i can get a state of the art radio for that. the px 300 is not cheap or plentiful. the px500 seems to be the holy grail.
i have an issue with you attempting to talk down to me and be full of shit at the same time. i dont need a packset as i am happy with my motorola gear and all of it , although out of date is more up to date then the crap you are peddling...

[NQ6U]

carl
i currently use a couple of maxtrac radios on 70cm. i bought my first one off ebay for 25 after shipping.

I did a Google search on Motorola Maxtrac radios and it looks as if you really need to know what you're doing if you're buying them off eBay to make sure you get something you can actually use. It would be just my luck to end up with something that will only be useful as a doorstop.


the trick is in the programing. software belongs to motorola and they do not like to share. there are quite a few hams around that use these radios and might have access.

That Google search showed up a number of sites that claim to have the software but you know how it is downloading warez from sites like that. I think I'd want to run it on a VM just in case there's an unwanted payload aboard.

[KA5PIU]

Hello.

I guess you do not get it, I am not peddling anything.
Talk down to you? no, you simply do not get it.
I do not sell Motorola radios, it really is that simple.
If you can get a state of the art radio for $75, buy it, again, I do not sell Motorola radios.

[WØTKX]

A big deal is the type of serial port UART that is used in the computer. True Story.

This can irreparably toast some Motoralas. Hint... find an old 286 PC. :yes:

Ahem. Is this a HamSexy thread? :mrgreen:

[kb2crk]

Hello.

I guess you do not get it, I am not peddling anything.
Talk down to you? no, you simply do not get it.
I do not sell Motorola radios, it really is that simple.
If you can get a state of the art radio for $75, buy it, again, I do not sell Motorola radios.


well cowpie, i would not buy a radio from you if you were the only one selling.
i have a uhf HT750 that i use on 70cm's that i paid 75 dollars for.
oh yeah, i get it. you are full of it as usual.

[kb2crk]

A big deal is the type of serial port UART that is used in the computer. True Story.

This can irreparably toast some Motoralas. Hint... find an old 286 PC. :yes:

Ahem. Is this a HamSexy thread? :mrgreen:

the maxtracs are hard to brick. (thank god) lol
i use an old PII machine with the processor cache turned off and the clock speed turned down to 66mhz.
there are a ton of them on ebay but as you said there are quite a few that will not work.
you can find them for sale elsewhere and can get them cheap and sometimes even programmed.

[KA5PIU]

Hello.

Motorola is very hard to deal with when it comes to software.
http://www.repeater-builder.com/motorola/rss/rss-index.html
With the exception of government model Motorola and repeaters I make no effort to keep software driven radios going.
San Antonio and Bexar county went Pro-Voice a few years ago and all the new stuff is that or P-25 trunking.
So, I do things like take an old Compa-base and pull out the original radio and mount 2 Astro Sabre talkies in place that run P-25.
Motorola radios are very high quality and Motorola protects that.
After Monty Sisco died my "Fence" between the radio freaks and myself was gone and I simply do not want to deal with cops and the like directly.
Motorola had some concerns over "Nick" radios but when they understood that I would cooperate 100% it quickly became a non-issue.
But, back to San Antonio and Bexar county.
The local MSS screwed the local governments around so bad that they started over.
San Antonio bought some used STX radios and Motorola filed suit.
The new radios are the Harris jobs that do VHF, UHF, 700 and 800 MHz, Pro Voice and P25.
Motorola is not happy so there is to this day concern.
Just like MARS surplus, the stuff I get can not be sold or given away, almost a carbon copy of the MARS rules.
Except, I also have agreed not to work on anything but Federal law enforcement and fire radios and my own station.
Civil Air Patrol is involved with drug intradiction and so falls under the federal unbrella.
This is the agreemant I have and it has worked out well for me so I am sticking to it.
This agreement has been in place for well over 4 years so it is nothing new.

[kb2crk]

Hello.

Motorola is very hard to deal with when it comes to software.
http://www.repeater-builder.com/motorola/rss/rss-index.html
With the exception of government model Motorola and repeaters I make no effort to keep software driven radios going.
San Antonio and Bexar county went Pro-Voice a few years ago and all the new stuff is that or P-25 trunking.
So, I do things like take an old Compa-base and pull out the original radio and mount 2 Astro Sabre talkies in place that run P-25.
Motorola radios are very high quality and Motorola protects that.
After Monty Sisco died my "Fence" between the radio freaks and myself was gone and I simply do not want to deal with cops and the like directly.
Motorola had some concerns over "Nick" radios but when they understood that I would cooperate 100% it quickly became a non-issue.
But, back to San Antonio and Bexar county.
The local MSS screwed the local governments around so bad that they started over.
San Antonio bought some used STX radios and Motorola filed suit.
The new radios are the Harris jobs that do VHF, UHF, 700 and 800 MHz, Pro Voice and P25.
Motorola is not happy so there is to this day concern.
Just like MARS surplus, the stuff I get can not be sold or given away, almost a carbon copy of the MARS rules.
Except, I also have agreed not to work on anything but Federal law enforcement and fire radios and my own station.
Civil Air Patrol is involved with drug intradiction and so falls under the federal unbrella.
This is the agreemant I have and it has worked out well for me so I am sticking to it.
This agreement has been in place for well over 4 years so it is nothing new.

ok, whatever you say...

[KA5PIU]

Hello.

PX do not have a talkie inside, just modules.
Incorrect, in order to do Smartnet the units had to be updated.
True, there was no talkie housing but the motherboard inside was STX.
Not that it matters, as part of the deactivation process the crystals and frequency determining elements are removed.
In short, there is nothing but an unpopulated board that is not even screwed in place.
With that in mind, at the next municipal auction a few of the PX500 units will be listed.
This is nothing but a plastic box, no radio inside!
They were on municipal equipment and are in poor cosmetic condition, the bottom of the barrel at that.
But it is my understanding that one can bid from the internet.
This will be sometime next year so there is plenty of time.

[KA5PIU]

you make some good points but that is not the issue i have with rudy's statement.
as you can see from rudy's quote above yours he states that these are easy to find, cheap, and all you have to do is pull one walkie out and pop another one in.
problem one is they are not that common. problem two is there is almost no info on the px500 and how to align its amplifier to the different bands rudy states it can be used on.
most of them are crystal controlled and those that are programmable require you to write to the eprom.
so not simple and not cheap as rudy states.

Hello.

Since I had the time I dug into the other one.
As I was told, there is one RF module in the amplifier plus a small board, there is nothing to align as there are no adjustments other than power out and tilt to deal with, and that is all of 3 pots.
The chip is a 35/40 watt rated 800 to 1200 mHz mobile RF output module made for Motorola by Mitsubishi for 2 way service.
As is the case of broad band amplifiers, there should be a band pass filter for the frequency range of intended operation.
Since it is being operated ONLY in FM service and well within the power range there is not much of an issue and this was checked for purity with a spectrum analyzer.
But that does not mean they are all clean.
And, the VHF pack sets are very popular with rail fans.
The ebay listing was for some secret service model with whitehouse markings.
One configured for 800 mHz and otherwise normal is not all that hard to find cheap.
San Antonio went to M/A-Com/Harris by way of Dailey-Wells Communications who took the police and fire side equipment in trade.
3440 East Houston Street
San Antonio, TX 78219-3814
(210) 893-6500
The guy to talk to is Richard Wells but I do not know if police or fire had any pack sets.
There were a few that were in storage at public works that were being thrown out that I snagged 2 of.
That is as good as it gets.
Try to have a good holiday.
And if you do not find any this year there is always next year.

[KA5PIU]

Hello.

Here is the replacement chip for a 15 watt packset or motorcycle radio.
http://www.mitsubishichips.com/Global/content/product/hf/sirfpowermod/800m/800m/ra20h8994m.pdf
It was never intended to operate outside its band of operation.
http://www.mitsubishichips.com/Global/content/product/hf/sirfpowermod/800m/800m/ra20h8087m.pdf
Same is true here, the primary difference is that one is for 900 MHz and the other is 800 MHz in intended operation.
There is no sort of filtering to limit operation below the range of operation intended, it will work.
RF foldback is provided by the small board the module is mounted on and will operate at 27.185 MHz into a dummy load. ;)
I was incorrect in the original module, intended for a higher power radio.
http://www.mitsubishichips.com/Global/content/product/hf/sirfpowermod/800m/800m/ra45h7687m1.pdf
Setting the talkie to output only 100 milliwatts is super easy, I picked a talkie with a dead output section. ;)
The VX-7r uses a 2SK3476 final transistor that I quickly replaced.
The real reason I pick the VX-7r is the steep learning curve for a new radio.
I have a scuffed up VX-7r that I did not mind drilling the case up a bit for this project, 2 RF ports and a nice external connection.
In essence I am going to mount the AF unit very much like the original audio section of the packset was.

[NA4BH]

I bought a couple of them and made a Jaccuzi out of them.

[w2amr]

I miss humpy, sometimes.

[KC2UGV]

I miss humpy, sometimes.

Damn, that's a low blow.

[NQ6U]

I bought a couple of them and made a Jaccuzi out of them.

I built two laser death rays and a cruise missile with mine. Don't anyone piss me off, I'm warning you...

[KA5PIU]

Hello.

People are missing the point.
There is a lot of commercial radio equipment going out of service due to digital and 700/800/900 MHz.
An 800 MHz mobile can be had for cheap and if it has an output module in place of transistors it has a broadband high power amplifier.
At that point it really does not matter who built it, as the only parts of interest are the finals and housing, with things like a regulator being a bonus.
The goal is to take a talkie and boost power, RF, DC, audio, making it more useful.
Who cares who built it to begin with, it is now a project. ;)