View Single Post
  #278  
Old 01-02-2017, 05:41 PM
Crist Rigott Crist Rigott is offline
VideoKarma Member
 
Join Date: Oct 2015
Location: Waxahachie, TX
Posts: 1,519
Well, I just finished an IF alignment.

I followed the procedure as in the Instruction Booklet on page 4. Basically it went like this:

1) Hook up a VTVM - I used my Knight KG-625

2) Hook up a signal generator - I used my Eico 322. I know, I need to get a better generator. Maybe a BK E-200D.
I did use my 6J6 with pin 1 cut off to eliminate any incoming signal.

3) Connect a 3V bias battery

4) Preset all 5 coils either full in or full out.

5) Set signal generator to a specific frequency and tweak a coil to a max reading on the VTVM.

When done, I hooked up my O'scope and Eico 369 Sweep Generator to check the overall response curve. This was the waveform displayed:



Not even close!

So, with my diddle stick in hand, I first set the middle frequency of 24.75MC on the marker and then started tweaking till the marker was near the middle of the hump. A quick check to see if the 50% frequencies were anywhere close. They were not. After a lot of adjusting and getting a feel for which coil did what to the waveform, I ended up with a very decent waveform with the 50% frequencies right on the mark. This only took me several hours of being patient. I can't imagine doing this with the grand kids over!

Here is a picture of what the response curve is supposed to look like:


Here is the pip at 26.4MC:


Here is the pip at 23.1MC:


Here is the pip at 21.9MC:


Overall this alignment went a lot better than the Admiral 14R12 I did a few months ago.

I haven't tried it yet because I have to do the sound alignment next even though I tweaked the coils by ear the other day.

Stay tuned for a report on that.

Last edited by Crist Rigott; 01-02-2017 at 05:49 PM.
Reply With Quote