I think you will find that it was your cable, maybe wired incorrectly. It will have blown a little smd diode. It sounds exactly the same as the problem I had.

If you like, I could get my diagrams out and let you know the possible faulty component.

I recall having a similar problem with one of those. Have you tried programming it via the accessory connector ? It was a while ago, but now that I think about it, there was a faulty component in the head of the unit, maybe caused by a bad programming cable.. I will have to dig out my diagrams and h...

Does anybody have a schematic for the NEC pager programming interface ?? Its the one that does the 11A, 10A, 20x, etc. I borrowed one off a friend, but the circuitry in the DB25 connector is potted in resin, so I cant get to it easily. They are quite old now and you cant buy them anymore. I'd assume...

Hi koerner, I have successfully made a system to program the advisor pagers. The circuitry I used is the simpler UPI with the MAX232 serial chip and LM339 comparator. I noticed that the pin connections shown for the 3 contacts to the pager are wrong. The ground pin is the one closest to the edge. I ...

Excellent, thanks (again) for the info. I did the re-freq on one of the advisors following your procedure using the 455KHz IF and it worked well. Actually, after the re-freq, the pager would receive a test message from an r1500 code synth connected to an r2600 as a sig gen at a level better than it ...

That worked well, thanks !! So, how far can you move them in frequency before you need to start changing components ?? I have a couple around 148.8 and others at 149.8 I would expect that the 149.8 ones would need component changes ? tpg, your info and help has been excellent and is greatly apprecia...

Thanks for the info, TPG, I tried the red, up, left, green but nothing happened, no noise, nothing. The red led didnt light. I had fully turned the pager off before doing this. Do you do each one of these buttons in sequence or all at once ?? It tried both and no go. Also, I had a look at the receiv...

Hi all, I have recently inherited a few motorola advisor pagers. These would have to be my favourite pager - big display, easy to use etc. I need to change the frequency on them. At the moment, most of them are on 148.6375, some are on about 149.8 I have worked out the crystal calculations for them ...

While I can understand the problems some people may be experiencing with the big M, this kind of thing happens with many large companies. I too have had the problem of trying to find that horrid long part number for some bat-parts, but the M guys here in aus are quite helpful. I run a comms business...

Thanks, Tony. Your help is much appreciated.

Are the numeric 1200 and alpha 512 supposed to be the same ?

I'd tend to go along with the faulty chip cap theory. If the audio is distorted with the antenna on, it could be the RF getting back into the mic amp and swamping it. The chip cap, being a small value, would normally stop the RF from doing this. There may also be another small cap in the "front...

Hi guys, Great forum and thanks for the batlabs site. I have used the site many times and will organise a paypal donation. Is there a normal donation amount that people make ?? I have a quick question that I'm hoping somebody may have the answer to. I have a motorola R-1150B code synthesiser. For th...