A simple VXO

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A simple VXO

Postby NT9K » Wed Nov 17, 2010 12:31 pm

Here is a new project that I am building for a friend. It's a simple VXO that will allow the frequency to be varied on an otherwise rockbound crystal transmitter. The variable capacitor is 365pF and will let the user swap out the inductor to change the range of slide. This has been a fun project and I should finish it today and start testing it.
Image
73, Bill - NT9K
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Postby G0KZZ » Sat Nov 20, 2010 1:00 pm

Another really nice build there Bill.

Mark.
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Postby NT9K » Sat Nov 20, 2010 3:01 pm

Thanks Mark, I just might have to make one for myself? I think if I do, I will add another socket for the smaller type 49 metal case crystals. They bend a lot farther than the FT-243's will and I have a couple transmitters that use the newer type crystals.
73, Bill - NT9K
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Postby VA7LAS » Sat Nov 26, 2011 10:16 pm

Hi - newbie here!

How far can you "bend" a crystal? Say, 7050 kHz FT243 - can I bend it as far as 7100?

NT9K, the link doesn't work for me. Can you repost please?

Lloyd
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Postby N6EV » Thu Dec 01, 2011 2:58 am

Lloyd,
With patience and the right technique, you should be able to bring a 7050 FT243 up into the 7100 range. It's been years since I've done it myself, but I had lots of fun taking FT243's down in the 6800 and 6900 range up into 40 meters. Technique is the key. Luckily, I compiled a set of responses to a question I posed on the old Boatahchor list back in the 90's. Tons of good information there:
http://www.n6ev.com/ft243.txt

Have fun!
73
Paul N6EV
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