[R-390] (Fwd) RE: GB> "Visual" alignment of receiver IFs...

[Kenneth G. Gordon]

OK, gang, here is the message I got from the GB list.

Ken W7EKB 

------- Forwarded message follows -------
From:           	"Ron D'Eau Claire" <rondec at easystreet.com>
To:             	"'Kenneth G. Gordon'" <kgordon at moscow.com>,
  	"'Old Tube Radios'" <glowbugs at piobaire.mines.uidaho.edu>
Subject:        	RE: GB> "Visual" alignment of receiver IFs...
Date sent:      	Sat, 5 Jun 2004 12:52:03 -0700

Ken, there's an excellent program called "Spectrogram" available on 
the
internet that runs on most Windows PC's. Basically what you need is an 
PC
running windows (95 or later), a sound card, and the ability to listen to
"band noise" from your receiver I.F. strip that's been detected and
presented as an audio signal to your computer sound card input. That's 
no
problem, of course, if you are aligning a fully-functional receiver. It
provides a great bandpass display showing frequency on the horizontal 
axis
and amplitude on the vertical axis. You just align the filters for the
desired bandpass characteristic you want, watching the display change 
in
real-time. 

The most recent version of spectrogram is available at:
http://tinyurl.com/3922r

It's shareware with a free downloadable trial version. The current 
version
has a timer that limits your use to 10 minutes a session (I believe it is)
before you must restart the program until/unless you register it. 

A version of the program that is still shareware (so you are encouraged 
to
register it and keep the developer at his keyboard <G>) but which has 
no
timer is available at Tom, N0SS, web site at:

http://www.qsl.net/n0ss/

Scroll down the page to locate 
"Download Spectrogram V5.17". 

Just below that link is another link:
"Download Spectrogram v5.17-specific (K2) alignment docs"

That's a PDF file that was written for aligning the Elecraft K2 I.F. filters
using Spectrogram. It's useful to you to see the menu setups in 
Spectrogram that
are recommended in this application, and it shows sample displays of 
what you'll
see.

Spectrogram is a really handy tool. I'm thoroughly spoiled after having 
used a
signal generator and meter for so many years <G> 

Ron AC7AC

-----Original Message-----
From: owner-glowbugs at piobaire.mines.uidaho.edu
[mailto:owner-glowbugs at piobaire.mines.uidaho.edu] On Behalf Of 
Kenneth G.
Gordon
Sent: Saturday, June 05, 2004 11:43 AM
To: Old Tube Radios
Subject: GB> "Visual" alignment of receiver IFs...


Sometime back someone here (Bob Roehrig?) mentioned that one 
could use a computer sound-card and various bits of software to do a 
visual alignment of a receiver IF instead of using a 'scope and sweep 
generator.

Would whoever mentioned this please go into some detail on it?

I am about to start doing many alignments and need this info, or where 
to find it, and my old eyes are too weak to squint at the scope in the 
dark.

Ken W7EKB



------- End of forwarded message -------