[TMC] Odd plug-in on FFR receiver

[Nick England]

Thanks, Roy - maybe JP will pop up with the applicable TMC documentation.
Or maybe this was a mod made by another contractor or USN.
Nick England K4NYW
www.navy-radio.com


On Sat, Jun 15, 2019 at 3:32 PM Roy Morgan <k1lky68 at gmail.com> wrote:

> Nick,
>
> I used to own such a receiver.  One of my plug-ins had an octal socket on
> a little bracket installed where the normal (HC-6?) crystal is on normal
> plug-ins.  You can see that addition to the front panel in the photos.  The
> socket was meant for the small round crystal ovens such as are found in the
> R-390A 17 mc oscillator.  The added socket had 6.3 volt filament  power in
> addition to the connection to the oscillator circuit for the crystal.
>
> I strongly suspect that the odd things seen in the photo are simply larger
> crystal ovens, quite likely more accurately controlled in temperature than
> the small round ones we are more familiar with.
>
> Roy
>
> > On Jun 15, 2019, at 2:46 PM, Nick England <navy.radio at gmail.com> wrote:
> >
> Three of the FFR receivers (AN/FRR-49) have a very odd "something"
> >
> > http://www.navy-radio.com/commsta/iceland/iceland-jd-1705-09.jpg
>
> Roy Morgan
> K1LKY since 1958
> k1lky68 at gmail.com
>
>
>
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