Re: DSB transceiver for Digital mode

Adam Rong


Pulling with NP0 capacitors will not generate too much stability issue. Normally inductors are drifting much. However, you are correct that 20m crystal is more unstable, but with the heating solution, it is much better and it won't have problem to make QSO. Adding heating resistor does have limitations, for example, if you use with car battery, the voltage varies with charging and the crystal frequency will vary as well. That's why we need regulated power supply or battery pack.

I customize all the crystals from a reliable supplier.My crystals for KN-Q7A, CS-series, CRK-10A all come from them.

I have all the parts ready and ready to ship hundreds of kits now. The first batch is 350 kits. Let's see how soon it will be gone.


On Thu, May 9, 2019 at 6:50 AM Ron Stone <rsstone2@...> wrote:

Thanks for your helpful, informative responses.

So it sounds like the 40 meter version may be significantly more stable than the 20 meter version because of the lower frequency crystal.  In addition, the 40 meter crystal doesn't have to be pulled like the the 14.070 MHz crystal which eliminates another possible source of instability, correct?  Does this mean the heating resistor is more optional for 40 meters?

Also, what is your source for the 7.074 MHz crystals?

Thanks again for your help and I'm glad to see we can order now!


Ron (KA3J)

Adam Rong

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