[ARC5] 10 meter BC-454 - stabilized.

[Kenneth G. Gordon]

The last thing I have done to stabilize this monstrosity was to apply copious 
quantities of coil-dope around the base of the 12K8 mixer/HFO and on and 
around the  replacements for the can-caps there, and let the dope "set up".

Result: Pretty much successful.

There are still some bits of microphonics when the BFO is on and one gives 
it a good whack or two, but they are vastly reduced from when we started.

There are no microphonics with the BFO off. 

I am still using that badly damaged BFO-can assembly that came with the 
receiver. The new ones I ordered from Fair Radio Sales have not yet arrived.

At this point, the receiver is working well enough that I don't feel any 
particular urgency to clean the remaining microphonics up.

If I let it sit on the bench-top like one would do when it is being used 
normally, the stability is very good. Tuning is easily done, and there are no 
"bad habits"

Next week, I'll complete the final alignment and testing and will try to 
"characterize" the receiver.

I did notice that when tuning from one end to the other, there appears to be a 
section of that range that has noticeably lower gain than the gain at both 
ends of the tuning range.  I don't really want to mess with those split-sections 
of the tuning cap, but may have to.

I may need some suggestions from the group on various matters.

I still consider this both a complete PITA to do, and an unnecessary kludge. 
A simple converter ahead of this receiver would have taken far less time, 
been more stable, and would have been at least as sensitive.

Still, it was a real "learning experience", I suppose...

It was somewhat disconcerting to me to find such seemingly little things 
cause such big problems.

Kenneth G. Gordon W7EKB

"Courage is being scared to death but saddling up anyway."--- John   Wayne