[R-390] Wanted: 14mHz Crystal

[Larry Haney]

Thank you, Mike.

Regards, Larry

On Sun, Jul 5, 2026 at 4:36 PM Mike Peace <mike.peace at gmail.com> wrote:
>
> Hi Everyone,
> Here's the link to the document that Larry Haney mentioned:
> https://r-390a.net/R390A%20Ovens%20and%20Freq%20Stability.pdf
> Cheers,
> Mike
> VK6ADA
>
> On Sun, Jul 5, 2026 at 6:30 PM Larry Haney via R-390 <r-390 at mailman.qth.net> wrote:
>>
>> Hi all,  To get the best frequency stability out of your 390x read my
>> short doc: 'R-390A Ovens and Frequency Stability' on our website.  The
>> type of crystals do make a difference.  Here's a link:
>> R390A Ovens and Freq Stability.pdf.
>>
>> Regards, Larry
>>
>> On Sun, Jul 5, 2026 at 6:55 AM Francesco Ledda via R-390
>> <r-390 at mailman.qth.net> wrote:
>> >
>> > It probably doesn’t matter, as the turning point of the original R-390’s crystal is at the operating point of the ovens, and most owners keep the ovens turned off.
>> >
>> > Best, Francesco K5URG
>> >
>> >
>> > Sent from my iPad
>> >
>> > > On Jul 5, 2026, at 07:00, Bob kb8tq via R-390 <r-390 at mailman.qth.net> wrote:
>> > >
>> > > Hi
>> > >
>> > > A generic crystal from Digikey is not going to have the same temperature characteristic
>> > > as the original. The radio may drift a bit as a result.
>> > >
>> > > it also may not have the ability to tune to the correct frequency.
>> > >
>> > > For < $1, try it and see is not that bad an idea. Just be willing to check things out a bit
>> > > and possibly buy a couple candidates.
>> > >
>> > > Bob
>> > >
>> > >> On Jul 4, 2026, at 6:42 PM, Fred Moore via R-390 <r-390 at mailman.qth.net> wrote:
>> > >>
>> > >> Bill (and others needing crystals),
>> > >>
>> > >> 1.  I do have one from an R-390 (not A) oscillator unit.  Fair Radio was
>> > >> selling these for $20 near their end, plus shipping.  Payment by check.
>> > >>
>> > >> 2.  But other crystals will fail from time to time.  So I went on
>> > >> Digikey.com... They have a bunch of crystals, mostly SMD types.  These could
>> > >> be put inside the original holder.  Even MHz are pretty common there.  What
>> > >> about drive levels?  Is a tube osc too much drive for this little thing?
>> > >> There is a datasheet for it on this page.  So this approach might help others
>> > >> in the future.
>> > >>
>> > >> Here is one by CTS for $0.72:
>> > >> https://www.digikey.com/en/products/detail/cts-frequency-controls/406C35B14M00000/604558
>> > >>
>> > >> So this approach might help others in the future.
>> > >>
>> > >> -Fred
>> > >>
>> > >> ------ Original Message ------
>> > >> Received: Sat, 04 Jul 2026 05:22:44 PM GMT
>> > >> From: Bill Cotter via R-390 <r-390 at mailman.qth.net>
>> > >> To: r-390 at mailman.qth.net
>> > >> Subject: [R-390] Wanted:  14mHz Crystal
>> > >>
>> > >> Happy July 4th!
>> > >>
>> > >> Does anyone have a donor crystal bank with a 14mHz crystal they
>> > >> would be willing to part with? Please advise with price + shipping
>> > >> to my QTH (below).
>> > >>
>> > >> Thanks es 73 Bill N4LG
>> > >>
>> > >>
>> > >>
>> > >>
>> > >> ------------------------------------------------------------
>> > >> Bill Cotter, N4LG              E-mail: n4lg at qx.net
>> > >> 173 Carolyn Lane               Cell: (859) 552-7481
>> > >> Nicholasville, KY 40356-9340 https://www.qrz.com/db/n4lg
>> > >>
>> > >> ARCI #9878, QRPl #1646, QCWA #29393, FISTS #4535, NAQCC 7470
>> > >> ------------------------------------------------------------
>> > >>
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