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First tests of MFJ-1026

By Ken Alexander
March, 1998

During a weekend when conditions were pretty crummy, I got a chance to finally play around with the MFJ-1026, and I am pretty happy with it. 
I got the 1026 about three weeks ago and never did anything more with it than take it out of the box and have a look inside to see how the mods were done. I finally got a chance to do them.

Removing the components that make up the high pass filter was easy and took only a few minutes. 
I didn't have the materials to install the antenna "reversing" switch so I contented myself with just unscrewing the antennas from the back of the set, reversing and re-connecting them.  That's when I noticed what garbage the SO-239s are that MFJ uses...
God, what junk! 
You couldn't twist on a PL-259 onto the Main Antenna connector more than 1 1/2 turns unless you had a pipe wrench with you. 
The other two connectors aren't quite as bad, but you still have to apply an unreasonable amount of force to install a connector onto them.  I'll just replace them all with Amphenol SO-239s.

We had several antennas up this weekend.  The main antenna was our standard 1000' terminated beverage at 45 degrees to Europe.  Jacques d'Avignon installed a 500' unterminated antenna aimed directly south for beacons and South Americans.  The 1000' wire was on a multicoupler for all to use.
I set up two 100' wires parallel to each other, about 6' off the ground and aimed at a bearing of 135 degrees, mostly to stay out of the way of the other two antennas. 
The two 100' wires allowed me to null out locals and Toronto stations very well.  The setup also worked well at nulling LW beacons, however that night it wasn't sensitive enough to pull in any of the weak TAs on LW.

Later on Friday night I connected my feed from the multicoupler to the main antenna input of the 1026 and the 500' south wire to the auxiliary antenna input.  That setup wasn't satisfactory at all, but it could simply be that the things I was trying to null were a mix of skywave and groundwave signals.  That's my guess.

Anyway, on Saturday I pulled in the 500' wire, the two 100' wires, soldered them all together and added on some more wire to make up a second 1000' beverage which was installed parallel to the Europe wire, about 100' away, and unterminated. 
This setup worked the best. 
We had a two-hour window where we had some reasonable signals from Europe before the K-index jumped up to 4 or 5.  During that time I was able to null several pesky domestic stations that were splattering from nearby, resulting in some really clean audio from the TAs.

I also ran into an interesting phenomenon.  Once or twice I had to reverse the antenna connections because I couldn't get a null.
When the terminated beverage was acting as the auxiliary antenna there were several times when there wasn't enough signal from it to get a null without drastically reducing the Main Antenna Gain to to match the signal level from the Aux Antenna.  By the time I found the null there wasn't much left of the TA!
(I didn't know what to think of this at first but then I remember a little demonstration I did for Jacques of the directivity of a terminated beverage vs an unterminated one... the unterminated wire yielded a TA signal with lots of splatter where the terminated wire had much less splatter.)
Anyway, my theory is that the directivity of the terminated wire meant there was much less signal from the offending station for the 1026 to use even with the Aux Antenna Gain wide open so I had to back off the Main Antenna Gain to account for it. 
My bet is that if I had gone out and removed the termination, nulling with maximum Main Antenna Gain would have been much easier

Originally written in March 1998, in a report to Werner Funkenhauser, and can also be found on Funkenhauser's excellent web site.
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