[ARC5] BC453 FET BFO Success!!!

[Bob kb8tq]

Hi

I have several counters that are up to the task and a variety of GPSDO’s to clock them off
of. If we get all goofy about GPSDO’s not being good enough, I can fire up one of the Cesium
standards……

Any counter with an OCXO time base it plenty good enough for this sort of thing. If your counter
does not have one, you can buy OCXO based GPSDO’s on eBay for < $100 if you do a bit of shopping.
You can get them any day of the week for < $200. 

On a practical basis, injecting a stable signal into the radio and looking at the audio out of the 
BFO is a really good test. That’s what you have to get going to do any of these digital modes. 
Since you have to do it anyway, there really is no overhead to the test other than the signal 
injection. That part of it is a < $20 adventure (or free …). 

If you get into trying to characterize this or that oscillator, it’s not at all a simple task. Temperature 
stability, initialization (warmup), aging, random walk, voltage changes, and a bunch of other things
all get into make it a mess. Separating each into a single number (or even a graph) takes a lot
of effort. Without separating them, you quickly get into a “my results are this” vs “your results are
that” kind of discussion. Comparing one to the other …. not so much ….

Bob

> On Dec 18, 2017, at 12:09 PM, MICHAEL ST ANGELO <mstangelo at comcast.net> wrote:
> 
> Does anyone have a frequency counter with a decent timebase to measure the drift? We've been speculating about the drift for days...
> 
> Mike N2MS
> 
> 
> 
>> Even at the time that I used Spectran software coupled to the output of my BC-453 all lines 
>> in the waterfall display were straight after the receiver was allowed to stabilize. There were 
>> very slight drifts back and forth, of course, since at the time I was not using stabilized 
>> voltages, but there was most certainly no continual sideways drift of any of the lines in my 
>> waterfall display.
>> 
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html