[Premium-Rx] harris tunable bypass filter 10073-6550

[eugene at hertzmail.com]

Hello all,

I've been working on an RF-1310 to bring it back up to spec. I
discovered a problem in the tunable bypass filter, employed as the
post-selector. 

It seems there are two major versions of this (as read about in the
premium-rx archives dating back to 1999).  The more common version seems
to be a digitally tuned bandpass, model numbers similar to 10215-6600
(and -6650, and others?) a photo of which can be seen here:

<http://murphyjunk.bizland.com/sitebuildercontent/sitebuilderpictures/23
68APRE.jpg>

This is not the model I have. I have an earlier model which apparently
is a continuously variable filter that is somehow voltage controlled.  A
photo of mine can be seen here:

http://www.hertzmail.com/urt-23/RF-1310/IMG_6091.JPG
http://www.hertzmail.com/urt-23/RF-1310/IMG_6092.JPG

I am looking for the manual to this earlier model, again with the part
number 10073-6550. Anyone have it electronically or otherwise? I would
gladly pay copying and shipping costs. Would also gladly make the copies
and send the originals back if that would be easier.

THE PROBLEM:
I took some measurements using a sweeper and my 8568B. I found that
2MHz-29.999 MHz looks excellent with the notable exception of 8.0MHz
through 9.9MHz everything on either side of this range looked excellent.
Here are some photos.

Good showing 6MHz profile (typical of all ranges): 
http://www.hertzmail.com/urt-23/RF-1310/6MHz-Bandpass.jpg

Bad showing 8MHz profile: 
http://www.hertzmail.com/urt-23/RF-1310/8MHz-Bandpass.jpg

6MHz profile is typical of all ranges but 8.0-9.9MHz. You will also note
that this shows the proper -6dbm loss through the filter (sweeper was
0dbm). On the 8MHz you can see a peak at about -23dbm, way off.

So I'm open to suggestions, but the manual is probably where I should
start first. 

Thanks for the bandwidth!!
Eugene W2HX