[ARC5] SCR-522 components

[Clare Owens]

Well, my experiences were exactly opposite back in 1957.  The transmitter
conversion was a relative snap and the receiver tunable mod never worked at
all.  Of course i was a high school senior with only a Triplett 310 VOM to
work with...

YMMV as they say.

Clare

On Tue, Aug 8, 2017 at 3:35 PM, Mike Everette via ARC5 <arc5 at mailman.qth.net
> wrote:

> Believe it or not, the receivers were much easier to convert than the
> transmitters.  QST and CQ published articles on doing this during the late
> 40s and early 50s.  It was not that difficult to make them tunable and
> bandspread the tuning to cover the 2 meter band.  Notice, I didn't say it
> was quick and dirty; this did require some disassembly of the equipment and
> of the receiver front end to avoid breaking the ceramic shafts in the
> tuning capacitors when removing plates to accomplish the bandspreading.
>
> My 522 receiver, so converted, had a squelch-opening sensitivity of about
> one microvolt on AM.  I later grafted an FM bandpass filter, second IF and
> detector from a Motorola packset receiver into it, using the first 2 stages
> of the 12 mc IF in the 522 as intended and rewiring the third one into a
> crystal-controlled converter using a 12SA7 to take that IF down to 455 kc.
> The result had amazing sensitivity, less than 0.3 uV if I remember right,
> but was very susceptible to drift from air currents in the room.
>
> Putting the receiver section into a case from a BC-375 tuning unit helped
> somewhat.
>
> I learned a lot from the 522.
>
> 73
>
> Mike
>
> WA4DLF
>
>
> ------------------------------
> *From:* Cliff Miller <cliff52 at gmail.com>
> *To:* ARC5 at mailman.qth.net
> *Sent:* Tuesday, August 8, 2017 9:53 AM
> *Subject:* [ARC5] SCR-522 components
>
> I see the second BC-325 transmitter in recent weeks on auction today.
> Channel control and jack boxes, even connectors show up regularly.  What
> happened to the BC-324 receivers?
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20170808/b9750492/attachment.html>