My omni 6 has a little problem also...if the rig isn't used for a while,
then I need to press the 40 meter button after rig boot up to get it to
transcieve on any band.
Donno what the problem is, but it's livable to me anyway.
----- Original Message -----
From: "Jack Mandelman" <modeler@bellsouth.net>
To: <tentec@contesting.com>
Sent: Friday, August 08, 2008 5:14 PM
Subject: [TenTec] Omni6+ (564) intermittent problem
> The other day I decided to check for propagation on 15M, and was
> surprised by how unusually quiet the band sounded; even the infamous
> 21.333MHz birdie was not to be heard! I then discovered that the
> maximum key down power output was about 2 watts, with very little
> sensitivity to RF output control setting. 12M exhibited the same
> symptoms, but the 564 operated normally on all other bands. After about
> 15 minutes the receiver abruptly returned to life and TX output was
> normal, on both 15M and 12M. This intermittent was repeatable for every
> one of the several times I checked the rig from a cold start. The
> problem has not been observed after the rig is warmed up.
>
> Based on the symptoms and examination of the schematics, I suspect an
> open in the bandpass filter for the L.O. output on the XTAL osc/L.O.
> mixer board. 12 and 15 meters share the same filter for the L.O. output
> before L.O. signal is sent to the BPF/front end board. The symptoms may
> indicate an open in this filter. I expect that the switching diodes
> (D38 and/or D43) to the filter are not blown, since diodes usually fail
> permanently in an open or shorted condition; an intermittent internal to
> a diodes is very rare. I would like to reflow all the solder
> connections associated with the L.O. filter served by these diodes.
>
> My question is how to best access the XTAL osc/L.O. mixer board. Has
> anyone had experience with accessing and removing this board? I believe
> it is under the FM and LL driver/NB boards. Haven't yet removed the
> covers to look at this problem. When I do, I will take many photos of
> the disassembly along the way.
>
> All comment/suggestions are appreciated.
>
> Jack, K1VT
>
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