Re: [IRCA] Antenna experiment

[Keith McGinnis <longwave@xxxxxxxxxxx>]

This setup sounds a little like a Wellbrook 1530 loop and a heck of a 
lot cheaper...Now if only I could solder plumbing pipe LOL.

Keith McGinnis
Hingham MA


Craig Healy wrote:
>>>I made a new loop antenna today, and initial results are very
> 
> encouraging.
> 
>>And then you'll build one for those of us on the list who are technically
>>challenged and ship it to us at a nominal cost...
> 
> 
> Heh!  If you can solder plumbing pipe, you can build this.
> 
> I had a chance to do a bit more testing.  I wound five turns of #16 wire
> tight through a ferrite toroid.  The toroid is the FT-240 size (2 1/2") of
> unknown composition.  A SO-238 was soldered to it.  It was then slipped over
> the copper pipe. I had 50' of RG-8 cable which I used to hook it to the
> homemade tuner I mentioned in my last message.  Then, a few feet of smaller
> coax to the truck radio.  It's a Blaupunkt MP74 which is a good radio.
> 
> At the moment, the copper loop is leaning against a fence next to my tower.
> Hardly optimum as one side is sitting on wet ground and it's a number of
> degrees off vertical.  I tuned through from 530 to 1710, and had good
> signals on every frequency not blocked by a local.  Far better than the whip
> antenna on the truck..  Some directionality was noted.  Boston stations were
> weaker as they were broadside to the way the loop was aimed.  Signal
> strength was almost too strong, especially on the low end of the band.
> There is no amplifier, all components are passive.
> 
> Having a loop which could potentially be turned with a rotor, and tuned at
> the receiver end is something I've been looking for.  I imagine this would
> work exceptionally well with the PalStar MW550P tuner, if I had one.
> 
> Tomorrow in the daylight I'll solder up the last connection, now that the
> toroid is on there.  I'll get some rope and hang the thing from some high
> point in the yard.  Then I'll bring out the R8B and see just what it can do
> on nulling.  At 10' to a side, it's fairly unwieldy.  If I build a permanent
> one, I'll use bigger tubing.  Less floppy when moving it.  Maybe 1.25"
> copper..
> 
> All in all, this was a heck of a lot less work to build than the usual box
> or spiral loop.  If it continues to work like the initial crude tests show,
> it's going to be a useful piece.
> 
> After I have a chance to do some further tests, I'll make a duplicate.  Then
> I will mount them at 90° angles and connect them to my MFJ phasor.  It may
> not even need to be rotated.  With one aimed north-south and the other
> east-west, a decent null ought to be possible around the compass just by
> phasing.
> 
> Sorry if this is rambling a bit.  I'm sorta thinking out loud as I write.
> 
> Craig Healy
> Providence, RI
> 
> 
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