[MRCA] Got a AM3349 with no HV. LV supply/fans OK

[Ray Fantini]

HV is not applied until several conditions are satisfied. The big one is the band centering motors that includes the drum being set to the right channel and the ATU that’s actually the output tuning setting the two switches that select what band the radio is in and if its running a 50 Ohm output or whip.
It’s a common problem where the motors freeze and wont move so the ATU never gives its go ahead and HV is not applied.  Also remember that if the filament timer is not set the HV cannot be applied. You can check that by looking at the primary voltage on the service meter. If you had something like an air flow failure you never get the primary voltage indication.
The HV supply is somewhat bullet proof but I have seen the relays fail.

Ray F/KA3EKH


From: mrca-bounces at mailman.qth.net <mrca-bounces at mailman.qth.net> On Behalf Of J Mcvey via MRCA
Sent: Thursday, May 26, 2022 6:34 PM
To: mrca at mailman.qth.net; army-radios at groups.io
Subject: [MRCA] Got a AM3349 with no HV. LV supply/fans OK

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Any known issues with the HV supply ...or do I have to actually troubleshoot the thing?

Jim
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