[ARC5] ARC5 Octal Crystals

[AKLDGUY .]

> ...plug it into Pins 1 and 3 of the crystal socket.

And note that the pins count anticlockwise when seen from above.

73 de Neil ZL1ANM


On Tue, Aug 19, 2014 at 1:11 AM, Mike Everette via ARC5 <
arc5 at mailman.qth.net> wrote:

> The earlier version of the CFI unit in the Collins ATC/ART-13 transmitter
> which uses a round-case, octal based crystal actually has a 200 kc crystal
> in an FT-241 holder inside that round case.  The FT-241 pins are soldered
> into the octal base.  I've opened one up and seen it myself.
>
> By the way, I wouldn't try unsoldering that crystal from the octal
> holder.  The crystal element is either welded or silver soldered to a pair
> of very fine wires inside the case.  After all these years, many of these
> crystals are prone to failure if disturbed by heat or shock.  Be Careful.
>
> To use an FT-243 type crystal (or any other holder with the same size and
> spacing for the pins) in the magic eye circuit of the Command Set, plug it
> into Pins 1 and 3 of the crystal socket.  I have just this minute consulted
> the Holy Books (original SCR-274N and ARC-5 manuals) to confirm this. Works
> great. I have a 7000 kc crystal (marked for use in the BC-1335 transmitter)
> in my BC-459 to give a handy low-end band edge reference.
>
> The ARRL-version crystal control adaptor unit was originally designed by
> Lew McCoy and featured in a November 1959 QST article, then in Handbooks
> from 1960-67 (or maybe 68).  It was something I built but didn't have great
> success with.  Drive to the final was low despite anything I tried.  My log
> filled up with one unanswered CQ after another.  I can only remember about
> half a dozen QSOs with that setup.  I ended up borrowing a DX-40, and made
> many more contacts.
>
> 73
>
> Mike
> WA4DLF
>
> --------------------------------------------
> On Sun, 8/17/14, Robert Eleazer <releazer at earthlink.net> wrote:
>
>  Subject: Re: [ARC5] ARC5 Octal Crystals
>  To: arc5 at mailman.qth.net
>  Date: Sunday, August 17, 2014, 10:53 AM
>
>  Perhaps we have discussed this
>  subject before and I do not recall, but is it possible to
>  plug an FT-243 crystal into the Command Set transmitter
>  crystal sockets?
>
>  I have a BC-652-A that has that arrangement, an FT-243
>  crystal rather than an octal socket crystal in the octal
>  socket, even though the manual shows an octal socket crystal
>  plugged in.  Robert Downs tells me this is normal, not
>  a kluge.
>
>  By the way, the ARRL handbook at one time had the plans a
>  circuit that enabled a separate crystal controlled
>  oscillator to be plugged into the 1626 socket.  In the
>  old days Novices could not use VFOs.  If you wanted a
>  crystal controlled Command Set transmitter, that would be
>  the way to go.
>
>  Also, by the way, Gordon's article on factory built crystal
>  controlled command set receivers is over at "Real Radios
>  Have Motors."
>
>  And maybe someone could explain the logic of designating an
>  FT-243 or FT-241 crystal the same as an FT-230 adapter.
>
>  Wayne
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