[Boatanchors] 1935 Transmitter Antique Crystal

[Richard Knoppow]

----- Original Message ----- 
From: "David Stinson" <arc5 at ix.netcom.com>
To: <boatanchors at theporch.com>; 
<boatanchors at mailman.qth.net>
Sent: Monday, February 13, 2012 3:38 AM
Subject: Re: [Boatanchors] 1935 Transmitter Antique Crystal


> Question was asked about that big antique
> crystal in the rig.  This letter copied to the
> list for general information.
> -----------------------------
>
> The big Blaley xtal wouldn't oscillate at first, either.
> I think the bakelite outgasses over the years
> and there was also a small amount of dust
> in the holder. I put a lint-free cloth on my bench
> and took it apart. Using a good, fine brush, I
> brushed out the holder and plates and gently
> brushed-off the blank, touching just the edges.
> As I'm sure you know, it's very fragile.
> Then I used mineral spirits to clean the
> plates and the blank. Put all the parts on
> the cloth and covered them with a tissue for
> several hours to dry. Gave everything a final
> brushing and "blow," then put it all back together.
> It fired right up, but still is not as active as some
> of my other xtals. Works OK with extra feedback.
> Actually, I've tried FT-243 and HC-6 with this
> rig at up to 600 volts on the plate. That's good
> for about 15 watts out, which is plenty if you have
> a good antenna. They seem to hold-up,
> but I haven't done an actual QSO with one.
> I'll give a couple a long test and let you know.
> 73 Dave AB5S

     It seems to me that I've seen several articles in old 
ham magazines and may be old ARRL handbooks about treating 
inactive crystals. I will have a look but don't have a 
specific memory of where I saw this.  I suspect this was at 
one time a common problem.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com