I have purchased one of these units it does all seem to be working well however the oxco is slightly off frequency, i have found the control for this on top of the oxco and also the calibration output control for the for the power meter ref but do not want to just adjust them in case theres a specif...

So after doing a bit of work on this cpm20 ihave found that the sensor wires have been pulled off the sensor chip as i thought i had nothing to lose i soldered them back on there normally welded but no joy the fet in the power body still seems to be ok, it looks like i should be able to buy a replac...

I recently bought a cpm20 20ghz frequency counter with power meter, the frequency meter works fine but i don't think the power meter does i bought a power head but all i get is a 1mw permanent signal. I have scoured the internet for any sign of a service manual but nobody has ever posted anything an...

Karl thanks for your response, i had already seen that page and unfortunately its of no use.
I have however found one the same on eBay for a reasonable price so will endeavour to purchase it.
Nigel

Just wondering if anyone has one of these power supplies and could help me out. Went into the workshop today switched on the supply with nothing connected and it blew up, after having it apart both switching transistors are blown and also several resistors, i have scoured the net for a circuit but t...

Ive got an ifr2399b spectrum analyzer and it fails the self tests on yaw filter and sometimes the others anyone got any ideas where the problem might lay.
I cant seem to find a service manual anywhere.

I recently purchased a transistor analyzer just wondered if any one on here might have any user information on it.
Its made by ML Aviation in the uk and may have military use. Cant seem to post a pic
Thanks

For all those who are interested i have recently taken the plunge and removed the RTC chip from my IFR com 120A and read it the original chip which is a dallas ds1286 was made about 23 years ago so im surprised the battery has lasted this long, anyway using a TL866 programmer set to 28c64 i was able...

Adrianh The copy of the manual ive got is a bit like that but the component layout is not too bad so ive written loads of stuff on they do take a bit of time to understand and im still not totally sure i understand them. I also have deviation and distortion problems you need to go to page 100 in the...

Adrianh
What part of the uk are you in i have got a laser scanner copier if it helps, where did you manage to get an original service manual from.

Adrianh
I have just repaired my baseband board i replace all the electrolytics and about 50 .1uf ceramic caps also quite a few of the 8 pin ics and several others i still have some faults.
I do have a service manaual but some of the baseband diagrams are a bit blurred.

Jry Ok had some major success today i got my new extender board built enableing me to work on the baseband card with it laying on top of the unit, i followed the alarm signal through the system until it gets to pin 1 on the large ADC ic this is where i thought i was going to have trouble. But after ...

Jry Thanks for the reply the temp sensor has about 200mv coming out of it if i warm it up with the hot air gun it starts to move up to about 400mv and then drops down the data sheet says about 10mv per deg so that seem alright to me. Even though the rf meter now passes it still does not show any rf ...

Wowbagger. Not sure if your still monitoring this but if you are i have a question regarding my com120a. I have spent quite a long time repairing the baseband module ive replaced all the electrolytics and about 60 100n ceramics and several of the op amps and regulators also a fair amount of through ...

Jry. Thanks for the reply about the 120, i am in the process of repairing the baseband card i will be replacing all electrolytics and a fair amount of the 100nf ceramics as they seem badly corroded also one of the 78l05 chips is bad as well. It will probably take a few weeks of careful cleaning and ...

Question for wowbagger. Hi i did converse with you a while ago about my com120a which has some problems, i am still trying to resolve them but was wondering as they are prone to realtime clock failures is there anything i can do while it still powers up to backup the info stored in the device so i d...

Wowbagger Put the ifr back on the bench today, i recently bought a nice quality rohde & swartz cmu200 so ive been playing with that. Anyway turned the ifr on and after self tests it showed the usual 3 failures i pressed the gen button to check what was working and then the screen started flashin...

Wowbagger Ok thanks i do have the calibration access code and ive had a look around in there but before i start that i need to finish repairing the baseband caps leakage problem. You suggested this little routine to someone else does this check everything on the board or are there any other little s...

My com120a ccasionally shows the input overload fault i think there is a temperature sensor in the input duplexer module located in the rear of the unit, if you can get it to work for a while go into the self test menus and there is a test for battery and temperature i think this is the input sensor...

Wowbagger

If you can only get part of the manual i would prefer the calibration section but if the schematics are available i would like them yes, thank you

Wowbagger

As you can see from my previous posts service manual unavailable anywhere i know you are designer not repairer but if you have any contacts that are able to supply a copy of the 120a service manual or even just the pages that relate to calibration i would be eternally grateful
Thanks

Update to my last post just had confirmation from usa office none available there either. Bummer!

I have finally recieved an answer from aeroflex it seems my request for a service manual has gone all around the uk but to no avail kelly johnson finally emailed me back to let me know there were none anywhere not even a pdf copy she suggested trying the usa so i have emailed them but dont hold out ...

Wowbagger I just found a post from someone else with the same problem with a com 120a devation, distortion and i also have power meter problems and you asked him to set the machine as though it were doing the self test in duplex mode i have done this and the results were as follows. Deviation 1.1khz...

Wowbagger I have a com120a and i was wondering what is required to get the SSB option is it a board that i could build or does it contain firmware, i presume as the model is no longer supported that the option is no longer available. Also is the service manual still available or have they stopped se...

short answer is that the calibration and alignment is in the service manual.( I have about three or four versions of the COM-120 service manual and it's in most of them ...the COM120C supplement is not a full SM if you find that one ) Usually the self test failing implies more than just an alignmen...

I have a com120a with a few issues the initial test shows 3 failures deviation, distortion and power meter its the power meter im more interested in, I have checked the digital board and found capacitor problems I've replaced all the electrolytic's and the lf412c's as one of them was badly corroded ...