Astro Spectra Fail 001 After PTT

[RAF]

I'know that there are issues with the aluminum electrolytic /\/\oto used in these units but my sympotoms don't seem to match up with the various posts here and elsewhere in which the Fail 001 simply comes up either intermittently or continuously flashing. This 800 MHz units is working fine on RX and keys up okay but drops TX after about 2-seconds and may not have modulation though it could be the service monitor doesn't see signal long enough to demodulate and reproduce. Anyone experience similar symptoms or have any thoughts relative to this? I don't mind replacing all the electrolytics but the discrepancy in symptomology makes me wonder if it will effect a cure or just be an exercise in futility that I could do without.

[RADIOMAN2002]

I think more info is needed. Front mount/rear mount, does it fail in vehicle and on the bench. Vehicle fail could be bad A+ wiring, thats coroded, and not providing enough juice during transmit, you could even have a high SWR causing the radio to freak out. Possibly the caps on the VCO are leaky, I'm not that familliar with the 800 mhz units. My first tests would be on the bench with know good bench cables, into a dummy load, checking for current draw. The if it's a rear mount change the head, front mount A-5 or A-7 change the head. Then start going into the radio and check the VCO lock line, you will need a service manual for anything inside the unit.

[Batwings21]

Fail 001 is synthesizer out of lock. Shows up only on tx probably because tx freqs are 45 megs away from rx ones in 800 and the synth can't lock there. Caps can cause this and would be my first try, but there are other things too.

[RAF]

The unit is a 45W A7 dashmount 800 MHz

I understand that the Fail 001 represents the synthesizer out of lock. Though there has been numerous case of Fail 001 appearing suddenly and erratically that replacing all the aluminum caps resolved, all the reports I've seen indicated the symptoms manifested themselves during RX. There was not a single mention of the failure being restricted to TX as it is in this case.

As to replacing the caps in the VCO, there are no aluminum electrolytics in the VCO and, according to /\/\otorola the VCO assembly is not a repairable item and if determiend to be faulty should be replaced carrier and all. As to the 45 MHz differential between TX and RX, the problem occurs in talkaround which tends to rule out the differential issue.

Though I realize that none of this conjecture rules out the caps and historical data would suggest they be replaced on principal, as Batwings21 suggested, there are other potential causes and though there are a significant quantity of documented cases, I cannot find a single one with these particular symptoms suggesting that this may stem from one of the other potential causes.

That said, AUX 1 and Aux 2 go low with TX as they should and the positive steering line hangs in at approximately 8.3V. Only the negative steering line and the synthesizer lock line shift inappropriately and then only after key-up has occurred. Based on date code of the IC's this unit is <=10-years old.

[Will]

Bad caps and capacitor leakage damage to the Synth section. Yes this can affect both TX RX and Talkaround.
Even replacing the aluminum caps will not (always) 'cure' the problems, the caps have leaked and that stuff damages the surrounding components.

"working fine on RX and keys up okay but drops TX after about 2-seconds " This is a known failure in Spectras, again this may be Synth lock failure and/OR
power control problems.

Raf, from the tests you posted, it looks like you will probably have to replace the RF/Synth board.

[W2PUT]

I just recently worked on a 800 Astro Spectra with the same complaint. Turned out to be the command board. The caps had not visibly leaked, and seem OK. A test board confirms that it was the command board. That was in March, ordered the board, and it's still back ordered (delivery date pushed out a couple times all ready) with an estimated delivery sometime in August.

Good luck!

[RAF]

I believe you have hit on the problem. According to /\/\oto, any rev of the HLN5558 will work and there is a seller on e-Bay that had 16 HLN5558L boards he claims are brand new. He was down to 12 by the time I decided to order one due to the extended backorder situation at /\/\. It is in transit so I cannot tell you whether it's a wasted $50 plus shipping or not but if you are in a hurt it might be work it. I'll update this when I receive the one I've ordered.