[Heathkit] Mohican, Any tips for aligning band "E"

[Philip Atchley]

Hi,

First, let me say that I've been at it for over 50 years (radio, not the 
Mohican ;-).  On past receivers I just kind of let the following problem 
go and "did the best I could".  This set is much worse though. Maybe 
somebody out here has a good tip or two. (I don't remember if the one I 
built in the 60's was this severe or not).

Today I decided to proceed with the alignment of the Mohican.  Not 
having the alignment pages, this is a "Generic" alignment, something I 
usually have little problem with. Especially on the simple single 
conversion sets like we're talking about here.

I have a fairly "basic", service type signal generator but I rarely use 
it for anything other than IF amplifiers. Instead I choose to use a 
homebrewed Xtal "marker generator" that creates  stable, selectable 
markers at 5, 2 and 1 MC as well as 500, 100, 50 & 25 KC increments. 
This works very well as I'm 'certain' of the generated frequencies and 
it has a level control and 50 Ohm matching pad at the output.

The problem I'm seeing on this Mohican is one I've observed on other 
single conversion receivers with low (455KC) IF frequencies.  That is 
one of oscillator pulling, especially on the higher frequencies.  On 
this set it is MUCH worse than most, making alignment of band E (20-30 
MC) nearly impossible.  Tuning the mixer stage and to a lesser degree 
the antenna stage pulls the oscillator all over the place.  So much so 
that I've NOT been able to get a suitable alignment.  I can set the 
oscillator so the dial reads the correct frequency, but trying to peak 
the RF stages pulls it off.

And one final Question.  Does the LO run above or below the tuned 
frequency on this tuning range?  With the fairly poor image rejection up 
there I'm sure I could align it either way.  The other bands were close 
enough in frequency that I didn't need to worry about it.

73 de Phil,  KO6BB
991 Different NDB's heard to date.

http://www.geocities.com/ko6bb/
Merced, Central California, 37.3N  120.48W  CM97sh 



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