If you're a radio technician who knows the M/A-Com Jaguar, 5100, or 7100 series radios, check in, please.
I really want you to check in if you're able to repair boards by component level repair rather
than do board swaps.
I'm learning component level repair on these radios, and the manuals do help, of course,
but troubleshooting information is very limited, in part because M/A-Com recommends that
component repairs be done that the factory. They're not exactly encouraging techs to
go in and start swapping out tiny surface-mounted devices. I can see their reasoning,
as it can be pretty nerve wracking even if you've got experience with surface mount rework
and repair.
I DO have surface mount rework and repair skills and I'm not afraid to change ANY part on
the boards, and have done so on numerous occasions. From the tiniest 0105 devices to
the Patti and Hillary chips, I'll change any of them and you'll never know they've been off
the board. No problem there.
What I'd like, though, is to pool knowledge with other techs so that a useful troubleshooting
guide can be put together for these radios.
I plan to start by probing a working radio and recording nominal signal levels and DC and
AC values in various modes, plus waveform captures as well. At many important
junctions in the circuit, of course.
I'd like to get to the point where I can quickly isolate problems correctly based on this
data, saving extra troubleshooting time.
For example, I have two UHF low split 7100s right now that have perfect transmitters but
have receiver problems. One's got a very deaf receiver but it's not completely dead.
But it takes a -55 dBm signal before the green busy LED lights up. But it unsquelches
normally, with good audio, and keypad and button tones all work.
The other one's receiver is TOTALLY dead. No keypad or other tones as well. A max
signal (+19 dBm) doesn't give a busy indication.
I attacked the audio section already as that's apparently a separate problem of its own.
But apparently the driver transistors and JRC audio amp chip were fine as the problem
persists. I'm starting to think that Hillary is whacked out although the transmitter works
just fine.
I have no evidence to support the idea that the RX VCO has any problem. I've swept
the entire band, and beyond, to see if I can stimulate any response out of the receiver,
but no, there's nothing there. And no error codes anyway.
I hope to, in the near future, be able to state "This component fails and reduces your
RX sensitivity by about 50 dB. Or that one fails and the receiver receives nothing at all."
And have it all on paper as an informed troubleshooting guide.
So who's able to participate and interested in helping? I'd suggest a divide and conquer
approach, with one person working on documenting the receiver and another working
on the transmitter, and another on the logic, or audio, etc...
Elroy
I really want you to check in if you're able to repair boards by component level repair rather
than do board swaps.
I'm learning component level repair on these radios, and the manuals do help, of course,
but troubleshooting information is very limited, in part because M/A-Com recommends that
component repairs be done that the factory. They're not exactly encouraging techs to
go in and start swapping out tiny surface-mounted devices. I can see their reasoning,
as it can be pretty nerve wracking even if you've got experience with surface mount rework
and repair.
I DO have surface mount rework and repair skills and I'm not afraid to change ANY part on
the boards, and have done so on numerous occasions. From the tiniest 0105 devices to
the Patti and Hillary chips, I'll change any of them and you'll never know they've been off
the board. No problem there.
What I'd like, though, is to pool knowledge with other techs so that a useful troubleshooting
guide can be put together for these radios.
I plan to start by probing a working radio and recording nominal signal levels and DC and
AC values in various modes, plus waveform captures as well. At many important
junctions in the circuit, of course.
I'd like to get to the point where I can quickly isolate problems correctly based on this
data, saving extra troubleshooting time.
For example, I have two UHF low split 7100s right now that have perfect transmitters but
have receiver problems. One's got a very deaf receiver but it's not completely dead.
But it takes a -55 dBm signal before the green busy LED lights up. But it unsquelches
normally, with good audio, and keypad and button tones all work.
The other one's receiver is TOTALLY dead. No keypad or other tones as well. A max
signal (+19 dBm) doesn't give a busy indication.
I attacked the audio section already as that's apparently a separate problem of its own.
But apparently the driver transistors and JRC audio amp chip were fine as the problem
persists. I'm starting to think that Hillary is whacked out although the transmitter works
just fine.
I have no evidence to support the idea that the RX VCO has any problem. I've swept
the entire band, and beyond, to see if I can stimulate any response out of the receiver,
but no, there's nothing there. And no error codes anyway.
I hope to, in the near future, be able to state "This component fails and reduces your
RX sensitivity by about 50 dB. Or that one fails and the receiver receives nothing at all."
And have it all on paper as an informed troubleshooting guide.
So who's able to participate and interested in helping? I'd suggest a divide and conquer
approach, with one person working on documenting the receiver and another working
on the transmitter, and another on the logic, or audio, etc...
Elroy
