Re: Racal RA-6790GM/R2174 New to Me
¿ªÔÆÌåÓýHi Peter, ? Thank you for the suggestions. I have a couple hours today to work on it. So far found two open traces on the A6A2 board, repaired them but still have issues. I tested all of the traces as well as their connections to the front panel ¨C everything seems intact now. ? I have a feeling that the A6A2 board will be replaced soon¡¡¡ ? What serial number is your radio? Mine is 3265 on the Racal ID plate and 3198 on the R-2174 ID plate. ? Tom W3TA ? From: [email protected] <[email protected]> On Behalf Of Peter E via groups.io
Sent: Friday, November 29, 2024 10:14 PM To: [email protected] Subject: Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me ? Hi Tom, ? I have just finished repairing an RA6790 and its a very nice receiver when its going! I am no kind of expert on these but I can answer some of your questions. The battery in mine (and I assume yours) should be 2.4V. Just replace it with any NiCad battery pack with that voltage - many cordless phones have similar batteries, and you can just velcro it to the side of the case somewhere. Mine exhibited all sorts of strange behaviour till I replaced it - would start doing a BITE test then hang at some point. ? The bulbs on my display were all burnt out - I have now replaced all of the bulbs with green SMD LED's and 4K7 resistors - see photo attached. ? Two of the tantalums were shorted in mine - in the First mixer (A2) and had taken out a choke as well. I am not normally a fan of shotgun cap replacement but am now tossing up whether to replace all the rest - thoughts anyone? I noted that they were 20V tantalums running at 16V - not enough safety margin I would suggest.? ? The three transistors in A2 seem to run VERY hot! I added some additional heatsinking - not sure if its necessary but cant hurt. ? Yours sounds like it may have issues with the A6A2 board. replcae the battery first then go from there I would suggest. Hopefully you proms are not damaged. ? Cheers, and good luck! Peter - VK2AN ? |