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Spectra with NO PL/DPL on transmit

Posted: Wed Dec 07, 2005 12:00 pm
by rocketman
Not sure if this has been discussed before. I have a D27 Spectra and for some reason, it will not transmit either a PL or DPL. I checked the programming and it shows correct. This also happens in direct (talkaround). It receives PL and DPL just fine. Audio deviation sounds good in carrier squelch, and MDC works fine. Does anyone have a clue why this might be occuring.
Thanks,
Dave

Posted: Wed Dec 07, 2005 1:01 pm
by RKG
A radio can sometimes file to send DPL because of deviation asymetry. There is a section in the Spectra book on this. I've never heard of that interfering with the sending of analog PL, though.

Can you get access to a service monitor and check deviation levels?

Posted: Wed Dec 07, 2005 2:06 pm
by xmo

Posted: Mon Dec 12, 2005 9:00 am
by rocketman
Okay, I dumped all the conventional channels out of the radio except for the 1 trunking channel, now the radio does the self chk/fail 1/90 loop. The fail loop is only visable with power supply voltage lowered to 6-7 VDC. I cannot read the radio, as the serial bus is constantly busy....any thoughts on getting out of the repetitive loop, tried lowering then jacking up the supply voltage as well as the home/dim button toggling. Command board fuse checks okay.

Posted: Mon Dec 12, 2005 5:45 pm
by Jim202
Why would you want to lower the supply voltage to that level? The radio won't work at that low of a voltage.

Jim


rocketman wrote:Okay, I dumped all the conventional channels out of the radio except for the 1 trunking channel, now the radio does the self chk/fail 1/90 loop. The fail loop is only visable with power supply voltage lowered to 6-7 VDC. I cannot read the radio, as the serial bus is constantly busy....any thoughts on getting out of the repetitive loop, tried lowering then jacking up the supply voltage as well as the home/dim button toggling. Command board fuse checks okay.

Posted: Tue Dec 13, 2005 12:01 am
by Will
Jim, this is one of the trouble shooting 'tricks' on Spectras. It changes the way the uP section "wakes up".

Posted: Wed Jan 18, 2006 7:34 am
by rocketman
ended up changing out the command board and now all is well...I am guessing a problem with the SM caps...

Posted: Wed Jan 18, 2006 9:40 am
by Jim202
I don't remember off the top of my head right now Will, but there is a voltage sensing circuit in the Spectra that looks at the incoming voltage. If it is too low, it causes a reset of the micro and it tries to reboot the micro. When the voltage is too low, all you get is a constant reset of the computer or it fails to even power up.

Please tell the rest of us what this trouble shooting trick is that your talking about by using a low voltage. I can't see how the circuitry will even allow the radio to power up under this low voltage condition.

Jim

Will wrote:Jim, this is one of the trouble shooting 'tricks' on Spectras. It changes the way the uP section "wakes up".

Posted: Wed Jan 18, 2006 10:15 am
by kb0nly
From the batlabs site:
Hook up the Spectra to the RIB in the normal way for programming. Connect the Spectra to a variable voltage power supply, ideally one where you can switch the output voltage. Now power up the Spectra at about 6 or 7 volts. When the self check display first comes up quickly switch the power supply to the regular 12 volt level and the Spectra may stay on.
I know FIRST HAND that this does work, though i don't know the details of exactly why. I had a VHF that was looping and i tried this, figured what the heck, and it worked. The radio stopped looping long enough to dump a new codeplug to it.

Posted: Wed Jan 18, 2006 10:16 am
by rocketman
once the self chk display comes up, you must at that moment turn up DC voltage up to normal

Posted: Thu Jan 19, 2006 7:15 am
by adfradiotech
RIPLEY's (believe it or not)

THAT TRICK "does work" .........