[Hammarlund] Sweep-alignment.

[Bob Camp]

Hi

I *think* the setup was a pretty typical Kay sweeper and logifier(?) log to linear detector. The display looked more like a TV set than a normal scope. The gal doing the job (when complemented on the speed) mentioned that “I’ve been doing those since before you were born sonny …”.

She had a series of shorts and resistors that went on the tanks in the main filter. I suspect it was a pretty typical short and load alignment. Click peak, click dip, click peak … on you go. 

Bob


On Jul 28, 2014, at 11:20 AM, Kenneth G. Gordon <kgordon2006 at frontier.com> wrote:

> On 27 Jul 2014 at 21:38, Bob Camp wrote:
> 
>> By far the most impressive job I´ve ever seen (in 50 years doing this) was on
>> the production line at Motorola. They had a setup for doing 455 KC IF´s with a
>> sweeper. The gal could do an entire IF from off the chart to dead nuts in spec
>> in under 20 seconds. That´s crazy good for a > 16 can IF (including the 
>> filter).  It was an amazing feat that I´ve never seen equaled. 
> 
> Man! Would I ever have loved to see that, and to learn how it was done!
> 
>> Anything I´ve ever tried to do, you need to slow things down so much that the
>> sweep is a bit of a pain to use. It works much better on wide band stuff than
>> narrow.
> 
> Yes. Too fast of a sweep can make the tuned circuit ring which causes the 
> display to be difficult to analyze.
> 
> Lately, I have been using a cheap B&K Sweep Function Generator to both 
> FM the signal generator (HP-8640B) and to simultaneously sync the scope.
> 
> Works well for normal vintage receiver's 455 Khz IFs, but I have not yet tried 
> this method with "tighter" IF stages nor crystal filters.
> 
> Ken W7EKB
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