[Heath] SB-101 100khz crystal ajustment

[Kenneth G. Gordon]

On 14 Dec 2012 at 1:48, Jerry Rego wrote:

> Is there an alternate way to adjust the 100khz crystal on an SB-101. 
> I read the instructions in the alingment section of book and I really
> dont have a receiver that receives wwv.  Plus I don't really
> understand what they want me to do with it.

Hello again, Gus. If you don't have a receiver that covers WWV, then you 
would have to have a very accurate frequency counter to align the 100 KHz 
calibrator.

What you do when you DO have a receiver is couple the signal from the 
calibrator into the receiver, PLUS the signal from WWV via the receiver's 
antenna. 

You will then hear a beat between the crystal calibrators signal and WWV's 
signal. You then adjust the calibrator's small capacitor until you get 
zero-beat. 

You couple the signal from the calibrator into the receiver by wrapping a 
couple of turns of a long piece of insulated wire around the calibrator's tube 
so the wire acts like a short transmitting antenna.

> 
> Is there a point I can connect to the frequency counter and just read
> the frequency off or a place that I can compare it to a frequency
> generated 100 KC signal.

Yes. As I said above, take a longish piece of insulated wire, say 5 feet long, 
and wrap a few turns of the end of it around V-17, a 12AT7. With the 
calibrator turned on, there should be enough signal to activate a frequency 
counter, or to hear in a receiver tuned to WWV.

> 
> I have two frequency generators.. one that can put a 1kc signal
> modulated on a signal as well as a function generator that can produce
> a 100kc sine wave.

Yes, but you don't know if those are any closer to 100 KHz than your 
calibrator would be.

> On the frequency generator that puts a 1000 kc out I am not sure how
> close the frequency is.  But I can put the generated signal on the
> frequency counter (recently calibrated within the last two years) so i
> can suspect it is accurate.

Most frequency counters have an internal oscillator, usually a crystal 
oscillator, as their "time-base" which also sometimes must be checked 
against something extra-accurate, like WWV.

If it was me, I would use WWV.

Good luck.

Ken W7EKB