The AM Forum

Yep, that's what he said.

No trees required, 5 minute installation.
Try it yourself for Free!

So good it's been issued a US Patent.  ;)

Well if it worked great at HF, this would be in common use by all of us for a long time.  I quickly perused the patents.  They are from 1919 and 1920.  In those days the lower frequency range was in use and HF was not.

For surface wave signals in use at the time (and still are), the patented antenna may actually have merit.

The Air Force ICBM system I worked on in the early 1970's had HF communications at their launch control facilities.  Today they have gotten rid of the HF communications and have replaced it with satellite communications and an LF communications system.  The LF system uses an underground antenna.

The static solution is called FM.

Or more power.   ;D

How about combining the two and running full strap FM. :)

I recall reading about an underground antenna years ago.  Seems the documentation recommended installing a counterpoise, about 120 feet long, elevated 65 feet or more, to improve the HF performance of the antenna.

A few years ago I laid out 500 feet of insulated wire right on the forest floor and recall picking up stations in Europe on 150 to about 170 kc's. I didn't do a lot of experimentation with it. I'm going to re do it this summer and I'll let you know the results on how it works on all bands. It was pointing due  west. Maybe I should point it in another direction?   8)

good one Rick :) ....John

You made a Beverage. Get the thing up in the air about 6 feet, terminate one end, feed the other through a 9:1 transformer and you'll hear stuff few others can!

Looking at the advertising pix,..

If the drawing's accurate it could be a ferrite loop-stick (mag. wave pickup) with one lead grounded to the casing, the other to the "lead-up."

It should work well at BC freq's.  Especially if in the middle of a populated region. heh, heh.  Think I'll make one up and try it on BCB.   

Oh, I should put the ferrite on a buried roundtable with an antenna rotator above ground.  If any of the thought police ask, I'll just say I replaced my flagpole with an above ground well pump.

A whole new set of thoughts to disguise. -

Since the area where I have had my Graveyard Ant installed
for several years has become overgrown, perhaps I should try
one of these instead?  What bands will it cover? I use the
current one mostly for 160 and 75.

I recall from my AFMARS days several years ago, some discussion of using a 1/2 wave length of coax (terminated in it's characteristic impedance -- e.g. a 50 Ohm R) laying on the ground as a low noise receive antenna for some of the net frequencies down in the 3.2-3.3  Mhz range.

A 1/2 wave length of coax terminated in it's characteristic impedance laying on the ground shouldn't pick up anything.

But it would be low noise.   ;)

It's amazing what can be heard and what not.

Back in 1988 I had just finished a pair of 4X1's plate modulated by a pair of 3CX-2500's.  For a dummy load I used a large piece of plywood with 24 bulb sockets mounted on it. 24 bulbs X 100w each = 2400 W.

Anyway, I located the "dummyload" outside on the ground, under my metal trailer at the time. I spent the next 3 hours testing on 3885... testing 1-2-3, testing 1-2-3, K1JJ, K1JJ, YAY, Hellllloooo, YAAAAAY, YAAAAAY, etc.  The receiver was off, of course.  The bulbs were matched with an L/C circuit and were all lit brightly.

The next day I got on the air and Mark/ WA1FAF asked me what the heck I was doing yesterday. He says I was S9+20  70 miles away in Mass and interfering with his QSOs. 

 I wanted to crawl between the floor boards.

T

Here's one for y'all antenner guru's:

I've been looking for some way to reduce some of the summer statique and ambient line and urban noise. I have always pondered the thought of some type of "Beverage" or "Beverage style" antenner. Any of you that have ever been to my place know that a conventional Beverage would be impossible due to the size limitations of my yard.

however I have always wondered how it would work if I strung a receive antenna around part of the perimiter of my yard in a horse shoe shape. I could support it about 2-3' off of the ground with PVC spacers off of my chain link fence, and get about 250' of wire out there. Then terminate it and wind a matching transfoma somewhat like a Beverage.

I wouldnt expect the directional effect of a true beverage (obviously) but would hope for a noise reduction and descent reception on incoming high angle stuff.

Any thoughts out there? 

                                                                 the Slab Bacon

Y'all are missing a terrific low-noise receive antenna...

I suggest trying a tuned shielded loop. I've received AM BCB stations during the day 300 miles out on a 3-foot square one.

Quiet? YES!

Easy to build, a great weekend project.

OR,

Check out the HUZman's small receiving wire loops (search "K9AY") that he has pulled out from a short mast to cover the various directions.  K9AY's are somewhat less effective than a full blown beverage, but still have decent directivity.  Steve hears pretty well into Europe on 75M with them.


Sorry to say Slab, but the half perimeter "bent beverage" you described would perform poorly for this purpose.  ;D   There will be no real pattern cuz of not enuff wire - or nothing to phase it against. Plus the chain link fence can have a big effect on a beverage. Also, watch for the close proximity of your main dipole overhead... that will kill the patttern too.   Bevs are very sensitive to interaction. 


I've found through trial and error, it takes exact planning and modeling to phase an antenna properly to get nulls and forward lobes in the correct directions, for horiz and vertical angles. I compare directive antennas to squeezing a balloon and watching lobes pop out while others disappear. There is always some combination where the lobes can be coaxed to appear where you want and disappear where you want - but this is a critical setting and not found without planning, modeling and testing.... or using a proven design.  Even then, fine tuning it is often required to match the real whirl QTH condix.

T

I agree with Bill. The "shielded" loop is worth trying Frank. Take some scrap RG-6 cable TV hookup coax and form a 4-5 square/diamond on a spreader. I made my speader with PVC and a 4-way adaptor in the center. Place a 400 pF or so cap at the bottom and feed it there. Remove about 1" of the shield at the top (directly opposite of the feedpoint). You could build one in less than an hour.

Place it vertically in your yard, or even on your roof or the top of the tower. Set the tuning cap for the greatest received noise on the desired opetational frequency. Rotate the loop for mininum noise. High angle signals are unaffected by the orientation of the loop.

The loop will not necessarily reduce thunderstorm noise unless the noise from them is propagating in at lower angles and you can rotate the loop to null on the direction of the storm. For the amount of effort required, the shielded loop is worth a try.