[Boatanchors] WANTED: FT-243 Crystal for 7160 khz

[telegrapher at q.com]

I've got a fist full of 75 and 40 meter xtals here, FT-243 types of course and almost all of them are 200-300 cycles off what the label shows.  

Who knows if that's the way they were spit out at the factory or if it is just due to aging?  Close enuff for AM work though.

Larry
W0OGH


----- Original Message -----
From: Glen Zook <gzook at yahoo.com>
To: Al Klase <ark at ar88.net>, boatanchors at mailman.qth.net
Sent: Sat, 11 May 2013 21:39:22 -0400 (EDT)
Subject: Re: [Boatanchors] WANTED:  FT-243 Crystal for 7160 khz

Until November 1972, the Novice Class was limited to 7150 kHz to 7200 kHz.  On 22 November 1972 the Novice Class segment was changed to 7100 kHz to 7150 kHz.  As such, there may still be a lot of crystals in the 7150 kHz to 7200 kHz range hidden in junk boxes, etc., left over from the pre November 1972 era.

Companies like Texas Crystals, U.S. Crystals, P&R Crystals, etc., used to have available just about any frequency in the 7150 kHz to 7200 kHz range.  Those crystals were often relabeled surplus crystals.  Now I have no idea as to if they actually reground crystals to move the frequency or if they actually measured the actual frequency of the surplus crystal and, if it was not on the "exact" frequency as on the crystal holder, they just put a new label on the crystal with the frequency which was measured.  Probably, a bit of both!

For the less expensive crystals, the companies often advertised that one could order a specific frequency but the actual frequency would be like +/- a certain amount (often 5 kHz) from the frequency specified.  I do know that the crystals that I had when a Novice Class (late May 1959 until I passed my General Class in late October 1959)  had frequencies like 7156 kHz, 7173 kHz, etc., on them.  It was the same for 80-meter and 15-meter crystals.  That is, the actual frequency might, or might not, end in a "5" or "0".
 
Glen, K9STH


Website:  http://k9sth.com


________________________________
 From: Al Klase <ark at ar88.net>
To: boatanchors at mailman.qth.net 
Sent: Saturday, May 11, 2013 7:36 PM
Subject: Re: [Boatanchors] WANTED:  FT-243 Crystal for 7160 khz
 

Hi Lee,

I think that's going to be a toughie.  The main source of FT-243's / CR-6/U crystals was WWII surplus.  Literally millions were produced for the BC-611 handie-talkie (3885 was a standard freq) and the FM "Jeep Radios." Both were Motorola products, and to a great extent we're still living off the leftovers.  Unfortunately, the very common Jeep radio rocks came in 25 KC increments, 7125, 7150, 7175, etc.

Occasionally somebody would order up a custom crystal, but it may have been mostly a novice thing.  Their band was 7100-7150.

If it were I, I'd round up a couple 7125's (channel 328) or 7150's (channel 329), and sit down with some fine wet-or-dry abrasive paper, and move the darn things.  No, you can't afford to have me do it.

You might also scrounge a color-burst crystal from an old TV, and double to 40 meters.  3.579545 MC x 2 = 7.15909.  Maybe close enough for AM.
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