Yes, I'm aware of this and referenced GW4ALG's info in my first post.  My power 
cable uses 10-gauge on the high-current side and 14 or 16 gauge on the 
low-current side.  It's not the problem as the feedback is still present when 
using my Astron but disappears when I use the Astron in combination with the 
MFJ switcher.  I still suspect the Astron has a slight issue.
 
JDC
 
It may be your cable. The TR7 does have a hefty current drain on
transmit, but a 35 amp supply should run it with no problem (assuming
good filter caps). This is addressed in GW4ALG's Drake notes, here:

http://www.alg.myzen.co.uk/radio/tr7/mods.htm#4

This little jewel is so ofthen overlooked by power cable
homebrewers....

My approach was to use two independant feeders (both positive and
negative wires) from my 35-Amp Astron clone to the TR7 power connector.
The high current rail should be #10 or (preferably)  #8, the low
current rail can be #16 or maybe even #18. Check your local auto supply
store or stereo shop for suitable wire. I actually used GE Mobile radio
primary wire for my high current feeders; I don't know what guage it
is, but it's THICK. Designed to run 110 watt mobile FM rigs mounted in
the trunk. It works very well, and virtually eliminated pilot lamp
flicker on voice peaks. I also applied this methodology to my Heath
SB104A, with similarly satisfactory results. My recently acquired PS-7
has been given this treatment as well. I'll never use a common feed for
the high and low current rails again if I can help it. :)

73

-Jim

--
Ham Radio NU0C
TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, 
HyGain 3750, IBM PS/2 - all vintage, all the time!

HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/
http://radiojim.exofire.net
http://incolor.inetnebr.com/jshorney
http://www.nebraskaghosts.org



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