[MRCA] [spam] [ARC5] BC-221 on Shock Mount

[Mark K3MSB]

Hi MIke  (and everyone else that responded).

Mike,  thanks for the info.  I enjoyed reading your web page on this topic.

The mount is "legit"  -- It's an MT-269 AR:

[image: image.png]

As you might guess from the top of my unit, the original power circuitry is
not going to be found.

[image: image.png]

Most of the HB Power Supplies in BC-221s are good candidates for window
maker awards, but this one looks to be rather nicely built:

[image: image.png]

Looking at the photos / schematics on MIke's page,  it might be possible to
duplicate the original circuitry, but at this time I plan to fix the
installed HB supply (cap replacement, replace the selenium rectifier with
diodes, etc).

Yes, the unit has the calibration book:

[image: image.png]

Good stuff!   Thanks for all the info.

73 Mark K3MSB



On Fri, Aug 7, 2026 at 6:48 AM Michael Hanz <aaf-radio-1 at aafradio.org>
wrote:

> It's on my web page, Mark - a TS-164:
> https://aafradio.org/docs/TS-164.html
>
> 73,  Mike  KC4TOS
>
> On 8/7/2026 12:05 AM, Mark K3MSB via ARC5 wrote:
> > Hi Everyone
> >
> > I have a BC-221N that is not in the typical metal case for portable use.
> >
> > Rather, it's on a shock mount.
> >
> >
> > image.png
> > image.png
> >
> > I've not encountered one like this before.
> >
> > I know various bomber aircraft had a BC-221 (portable unit) stored on
> > board,  and I'm interested in learning when this type of mounted unit
> > was used instead.
> >
> > I didn't see anything in TM11-300.
> >
> > 73 Mark K3MSB
> >
> > ______________________________________________________________
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