Re: Bayou Jumper First QSO!

Jim Pruitt

Jim,  take a look at John Clements crystal page at:
near the bottom you will see that he is selling FT243 holders for $3.75 each with one of the HC49S crystals inside.  One of the available frequencies is 7.122mhz (or 7.110 or 7.114 from his 40M-B list.  You can get any of his many other  frequencies in those FT243 blank holders.  Also a 3 pack is $10 (and can be 3 different frequencies) plus shipping.  Since there is no danger of over driving those HC49 crystals they should work great in the BJ.  Take a look at Johns home page at  where he says he is working on 6 meter crystals.  John has started stocking a lot of different frequencies that we use and they are quite cheap.

I have no financial interest in this.  I am just a satisfied customer.

Thank you.
Jim Pruitt

On Mon, Dec 26, 2016 at 4:13 PM, Jim Sheldon w0eb@... [4sqrp] <4sqrp@...> wrote:

I picked up a 7.125 FT-243 off eBay for 8 bucks.  I can either load it down with graphite pencil markings on the quartz, or I may try to duplicate an old technique where a screw and knob were attached to vary the pressure on the quartz to lower the frequency a bit.  Depending on how active that particular piece of quartz was, I've seen good ones move 3 or 4 KHz down before they quit oscillating.  If you can find some old Pepsodent tooth powder (not tooth paste) you can use that, a toothbrush and a little water to carefully grind the quartz and raise the frequency a bit.  Never got one to move more than a KHz up though.  Down is much easier.

Used to play with this all the time when I was stationed in Japan back in 1963-1966.  Through the MARS program we had hundreds of FT-243 crystals available.  Now I wish I'd kept a few - LOL


Sent from my iPad

On Dec 26, 2016, at 5:39 PM, Johnny Matlock jomatlock@... [4sqrp] <4sqrp@...> wrote:

Ge Curt, 
I added a small 10-80 pico trim pot in series with my rock, then I could tweak it up a little?
Seemed to work well.
On Mon, Dec 26, 2016 at 4:28 PM rhulett1@... [4sqrp] <4sqrp@...> wrote:


Completed the build about an hour ago, took awhile to find the oscillator on the IC-728, ended up high by about 200 kHz so squeezed the coil, adjusted C30.  Now tuning 7010-7160 which suits me.  Plugged in a 7.050 FT243 crystal, transmits on 7.049. Not having much luck with the spotting procedure, need more practice I suppose.  Used the IC728 to get the receiver close to transmit frequency.  QRL a few times, coast was clear so CQ a few times.  K5ZSI about 130 miles from me answered, gave me a 569 report.

After verifying he wouldn't turn me in to the gestapo, told him was using a "spy radio" at about 2 watts powered with 8xAA cells.  It isn't in the wooden box yet so will hide it from the occupation troops in the cupboard when not in use until can finish the case. 

72, Curt KB5JO

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