[HBR] which receiver is THE BEST receiver

[N2EY at aol.com]

In a message dated 4/7/06 4:55:33 PM Eastern Daylight Time, 
amargosaent at iscweb.com writes:


> > What was used as the frequency standard?
> >
> > 73 de Jim, N2EY
> > ************************************
> >
> 3.5kHz HBR internal crystal marker oscillator was used.  Obiously, the
> marker also shifted some unknown amoun since it heated up right along with
> the rest of the receiver.    

Still, the 3500 kc. marker would be an order of magnitude more stable than 
the receiver. Biggest problem I can see is that you can't calibrate the marker.

A 100 kc standard can be calibrated against WWV before each drift run, and 
again thereafter.

A more accurate source would have been my
> 
> BC221/LM frequency meter after it had a 24-hour warmup.  As I ran the test
> 40 years ago the goal was to create drift data for use by W6TC (with whom I
> was working at the time) for his comparison with other drift results.  Ted
> insisted on using the crystal marker, so I took an identical approach in the
> interest of having my data use the same base as his.  I have neither
> knowledge or experience with the GB designs so cannot comment.  Hope this
> clarifies my original message for you.


Sure does! Thanks!

Which brings up a good point: what constitutes 'good' or 'bad' performance in 
many areas is a matter of personal preference and the application.

For example, a drift of 500 Hz would hardly be noticed on AM. On many data 
modes it would be intolerable. 

The operator who is working a hunt-and-peck contest might not mind drift that 
would drive a net operator bonkers. The contester doesn't stay on one QRG 
long enough to notice the drift, while the net operator is constantly struggling 
to stay on frequency.

I think one of the big reasons SSB was resisted by many was the drift issue. 
Rigs that were fine for AM were all over the place on SSB. In fact, I think 
many classic GB rigs - receivers and transmitters - were primarily designed for 
AM, with CW tacked on as an afterthought. (why else would so many of them have 
AVC and big S meters, yet lack a decent filter and resonable stability?)

---

One of the tricks I have used in drift testing is to zero beat the VFO or a 
harmonic with WWV. Fortunately, many of my designs have VFOs where this can be 
done directly. 

73 de Jim, N2EY

73 de Jim, N2EY