For some time now there has been a "Hunt for Red Oscillator" for the Big Talker transmitter to give it frequency agility.
For some time now there has been a "Hunt for Red Oscillator" for the Big Talker transmitter to give it frequency agility.
THIS little gold nugget will fit the bill just fine.
As can be seen in the link, that item sold..that's because I bought it! 😀
However these can be obtained from RFSource in Greece. I also ordered two from them, the SH101 and SH102. The SH101 covers 3Khz to 3Mhz and the SH102 covers 3Khz to 10Mhz.
My ebay purchase arrived today and as shown in the listing picture, comes with the DIP switches installed. The units from RFSource do not have the DIP switches installed, but can be obtained from any supply vendor.
This will be used as an emergency frequency generating device in my primary LPB TX 2-20 transmitter which currently is using the C-CUFF C-QUAM exciter driven by a programmable oscillator. If something happens to that C-QUAM exciter or the programmable oscillator, I can simply jumper to this PLL oscillator board and resume operations.
Though the SH102 cannot reach 13.560Mhz, it can cover the most popular SW frequencies.
But it's main use here will be to serve as a backup to the primary AM 1670 C-QUAM exciter's programmable oscillator module.
I love redundancy and ultra-quick backup solutions so that downtime is kept to an absolute minimum.
RFB
I had seen one of those a couple of weeks ago on Ebay and wondered how they faired...(were you bidding against me on that one?) Let me know on stability, I wanted to build one for myself but hadn't talked to anyone that knew anything about them...
" Let me know on stability."
Testing of the PLL will commence tomorrow and I will report the findings and maybe even a few pictures of the unit under test with my Motorola R 2012 D analyzer.
"were you bidding against me on that one?"
Well..if you were bidding...I guess I was! Sorry bout that! There was one bidder making a challenge up to about 1 day before the auction ended, but they did not bid any further so the price sold as shown was their highest bid...my highest bid was 48 bucks. 🙂
The units from RFSource are at a cheaper price, though they don't have the DIP switches, they are the same units.
There is another PLL oscillator up on ebay from RFSource. But ordering directly from RFSource, it's half the price plus the shipping...and the wait! 😀
RFB
Nice find RFB!
Regarding stability, I have tested a PLL circuit which uses the same type of crystal but at a different frequency and found that it is quite stable with temperature changes. The change in frequency from 38 to 110 degrees F was 5 Hz at 1680 kHz out. Quite adequate.
Frequency stability depends on more than just the crystal but such circuits can be quite stable.
Neil
Thanks Neil! The testing today was delayed by a drunk driver who decided that his vehicle would look better wrapped around a utility pole 4 blocks up the road. Knocked out power for 3 hours.
Testing will commence after turkey day...when I'm stuffed and can't move. 🙂
RFB
Aside from E-bay?
I can build things that are
pretty big, where the parts
have spaces between them,
but this would be a hard
build for me.
Are there any assembled modules
like this out there that don't
cost a fortune?
(My guess is probably - no.)
Also, I think it was you, Neil,
who made reference to a very
simple circuit that could go up
to about 2 MHz or so. Can you
reference what thread that was
om? You made some references, too,
RFB. Could you reference the
thread? Eyesight is down a little
this week, so if you guys told me
where to find those, it would be
easier than if I had to search for
the thread.
Best Wishes, always,
Bruce, W 60 HZ, X-13
Bruce,
I don't recall in which thread I mentioned the PLL I built so it is easier just to repost the schematic HERE .
Hope this helps.
Neil
I was bidding on that one, but once the auction price + shipping got up to what they sell for directly from the website, I stopped bidding. Then, after the auction was over, I realized that "some assembly was required" from the factory direct models...oh well, let me know how it works, thanks!