[Hammarlund] Sweep Method for Alignment (explain?)

[Kenneth G. Gordon]

On 8 Apr 2006 at 10:48, Leigh Sedgwick wrote:

> Hi Ken,
> 
> I have been following this discussion with great interest and it looks
> like a great way to align the IF stages of any receiver.

Believe me, it is really the only way to get a really good alignment of IF 
strips, especially those that have to be stagger-tuned. Although you can 
do it by taking readings and plotting a graph, that method is VERY time 
consuming.

>  So I started
> looking through some of the references I have here and stumbled across
> an IF alignment procedure in Bill Orr's 17th Edition handbook.

Oh, yes. Good old Bill.

> It differs slightly from the present discussion by suggesting the use
> of frequency modulation on the signal generator itself to do the same
> thing that the sweep generator is doing.

Yes. That works too. In fact, my RSGB handbook which is 
contemparneous with the Orr book has a project in the test section on 
building such a signal generator for the express purpose of aligning IF 
strips.

>  My HP8640B has FM capability
> down to 5 khz deviation.  Any thoughts on this method to accomplish
> the same thing?

I am glad you mentioned that. I have an HP-8640B also. As far as I 
remember, doing what you suggest is perfectly suitable and works at 
least as well as using a separate sweep generator. However, the 
problem with MY HP-8640B is that it doesn't reach down to 455 Khz. It 
stops at 500 Khz, and I need it to go down to about 400 Khz. And for IF 
strips at 100 or 50 Khz, unless I built a converter, it wouldn't help.

> I will soon have a HP3336C sweep generator here in the shop so after I
> get up to speed, I will try both methods.

When you do, I sincerely hope you post a DETAILED account to the 
list, or make your information available on a website somewhere. If you 
don't have anywhere to post it, I can provide a place.

> Thanks again for all the great information in these posts....

Well, we are all in a big community here and I, for one, thoroughly 
enjoy our discussions. I have learned so much from the lists I am 
subscribed to, it is almost as if I have gone back to school. So anything 
I can do to give something back makes me happy.

Ken W7EKB