[Boatanchors] 1935 Transmitter Antique Crystal

[Geoff]

----- Original Message ----- 
From: "Richard Knoppow" <1oldlens1 at ix.netcom.com>
To: "David Stinson" <arc5 at ix.netcom.com>; <boatanchors at theporch.com>; 
<boatanchors at mailman.qth.net>
Sent: Monday, February 13, 2012 11:27 AM
Subject: Re: [Boatanchors] 1935 Transmitter Antique Crystal


>
> ----- 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
>


Its still a common problem in vintage single crystal filters. The tried and 
true procedure of using a 99% Isopropyl alcohol still works well to restore 
even 30's crystals to full activity.

Ive also used it with various FT type holders from FT-243 to the big BC-610 
size in VXO circuits where activity is very important to the amount of 
"stretching" that can be obtained.

Carl
KM1H


 ______________________________________________________________
> Boatanchors mailing list
> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Boatanchors at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1424 / Virus Database: 2112/4807 - Release Date: 02/13/12
>