PA3CLQ's Leuke Linken Nr. 429


Marshall Emm at M-technologies --- POC Information

Marshall Emm runs Oak Hills Research and is just an absolute pleasure to deal with.

I own several of his wonderful kit radios.

Here is some contact info.

73s & Enjoy!

N4IVE - David Gale



Is there anyone here or at ARRL who is attempting to do anything about the intruder that has taken over 7055 - 7060 kHz??
It is now unusable much of the day, due to some kind of high powered "over the horizon radar" that has taken over this part of the band with a powerful band-blanking signal.
Annoyed - AF4K Bry Carling


I don't think I've heard it up here.

The only thing I hear is the "H" sweep, a data burst every two minutes that sounds like a Morse "H".

It starts down around 2 MHz and goes up to 8.

But not nearly as annoying as what you are getting.
Regarding the old woodpecker-- they used to say that it would QSY if you sent a string of dits at the same speed as the radar pulse rate...
73, Drew AF2Z

Hi Guys,

I've seen postings that reference a new Russian over the horizon radar is the culprit.

73, Art, W2NRA

And don't forget about this one as well:


It's pretty loud up here Bry. Around 10-20db above the noise floor on two diff. rcvrs with diff. antennas.

It is disrupting a prime spot on 40.

Hopefully its temporary...but we know how that usually goes.
73 de Bill K4JYS (NC)

It has been there for weeks now, off and on. Mostly on.
Sad - I think the Boatanchors and SKCC guys are hurting from this, given the popular calling frequencies of 7050 and 7055 are now swamped.
Does anyone know who to contact at ARRL Intruder Watch??
Or some other Intruder Watch?
Bry AF4K


It looks like ARRL is aware of these intruders based on the article referenced by Art.

However, given that OTH radar is undoubtedly military, I doubt that the ARRL, or anyone else for that matter, is going to have much influence with them.
Mike, W8DN


I would love to see the cease and desist order from an ARRL lawyer to the defense minister of a major country (possibly our own!) to quit harassing our hobbyists.

Better yet, I'd like to see their answer if they bother.
40 meters has ALWAYS been like this.

It's a feature!

Enjoy it.

BTW, great boat anchor station on your QRZ page.
Eric KE6US


During Feb SKS it wiped 40m out for me from SW Fla. It was from 7.045 to 7.065 and VERY LOUD.

Rest of 40m was fine.

Perhaps another reason to have, at least on 40m, a lower in the band hangout.

This would also help our members outside of NA.

73, Tim K9TM

Bry, are you able to record it?

I would like to hear what it sounds like.

73s & Enjoy!

N4IVE - David Gale


I just read this and checked 40M (have been on 30M this afternoon).

Don't hear anything like your intruder.

I did hear some strong back and forth DIGI signal (maybe Amtor) just above 7060.but not terribly wide band/

I will listen tomorrow morning also.

Maybe it's coming from Cuba ?

CW is Real Radio 73, John...K8JD


Thank you Bill. Yes, I will look it up and see what if anything can be done.
At this rate we are going to (de facto) lose a large portion of 40m CW.
Bry AF4K


You may be able to go onto

and check signal strength from SDR stations around the world... Maybe pinpoint its source...



Antenna for 6 meters.

I've got a 6 meter xcvr on the way, so I'm thinking about antennas for 6 m.

I am hereby soliciting ideas from the friendliest, most knowledgeable group of hams I know (besides the AMSAT group, to which I also belong, and which also contains the friendliest, most knowledgeable hams I know.)

I'm thinking that a vertical is probably best.

If so, what is the minimum height I can get away with for the bottom of the vertical?

If I went cheap and dirty (not unusual in my case) and put up a dipole, should it be oriented to propagate N-S or E-W?

All reasonable thoughts are appreciated!

Steve AI9IN


There are a couple of things to consider.

1) Polarization, vertical and horizontal.

Verical is more noise prone, but omni directional.

Horizontal is less noise prone and the halo works nice for omni directional.

2) Gain. Yagi and quad antennas are the basic choices.

It is nice to have the omni directional to catch band opening from anywhere.

Then switch to the gain antennas to bring them up in strength.
V31JP Joe


Hi Steve

Dipole: 1/2 Wavelength on 6M is 3M, so you'd want the dipole to be at last about 20 feet above the ground.

I ran a 5 element yagi at 18 feet for years and it performed well at that height.

Regardless of the orientation of the dipole, it will be pointing in the wrong direction.

This is especially true of 6M where the most prominent mode these days is Sporadic E, not F2.
Horizontal: 1/4 or 5/8 wave.
As Joe pointed out, a loop antenna works well for omni work.

Google "Loop Antenna" and tons of stuff will show up.
Two pieces of 10 foot TV Mast from Lowes and a low end TV rotator bolted to the side of a picnic table will work.

When 6M is open CONUS you do not need a lot of power / gain to work K, VE, XE, and the Caribbean.
Enjoy the "Magic Band" !
73 Mark K3MSB

If the band is open, it doesn't take much at all. Since I only operate 6m when the band is open, I use a Buddipole Dipole or sometimes a 5/8 wave 2 meter mag mount (which tunes on 6). I've even tuned up a random wire and it works great...again, this is not for weak signal work but for when the band is open!

Mike K3WAS


For the sake of simplicity I sure would try a slim jim.

Can be made out thin walled copper pipe OR 450 ohm line taped to some kind of non-metallic pole.

I just took down my 4 element Comet yagi because my space for antenna is extremely limited and there is virtually no activity on 6 meters where I live.

I am an old guy and not likely to see a good sun spot cycle for DX again.

Reason I like the slim jim is it has very low angle of radiation as compared to a 1/4 wavelength vertical with radials.

James Brock W7DAU


Sure a vertical, up 25-30 ft, is nice for local FM repeater work every day, but for the "SERIOUS" 6M SSB/CW DX work you need a Yagi, I would not mess with anything Less than a 4 element Yagi.

I have a Hy Gain 4 element, up only 30 Ft and wanted to get it a lot higher!!

I worked everything from the rocky mountains to Eastern Canada and down to the Carolinas and FL with 8 W SSB in one season !

CW is Real Radio 73, John...K8JD


6m CW & SSB are all done horizontally polarized CW between 50.075 and 50.100 (50.090 is the SKCC freq.) SSB is usually 50.125 up to 50.250.
I'm running a single element halo (Pars-End Tralo) at 45 ft. above ground which is 140 ft. ASL in Grid Sqr. FM18.

Running barefoot (less than 100W) I've worked the whole Eastern Seaboard to the Mississippi River and Texas.
My DX QSOs are Canary Is, PR, Barbados, Bahamas, & the Maritime Provences of Canada.

My best to the west is Idaho.

So when the Sporadic E-Skip is active, you can work much with just a halo.
It is amazing that when the CW portion of the band is quiet and I call CQ, I often get an answer.

If nobody is actually in a QSO, then most people think the band is dead.

But keep calling CQ and they will come out of their quiet mode.
Watch the 50MHz tab to see if 6m is open and where the QSOs are.
QSO/SWL real time maps - NA - 50

Good luck with your 6m rig and I hope to see you on 50.090 MHz.

Jim - N3ADF


Polarization is only important for line of sight communication.

Once the signals bounce off the ionosphere, it isn't very important.

If you can't put up a beam or dipole, you can get good results using a vertical antenna.

Andy, K2OO


What you get in band openings 95 % of the time, on VHF, is tropo enhancement , not the same as the usual normal days' F2 layer "SKIP" on the lower HF bands. E layer probably does mess up the polarization but it is only working about 5 percent of the time in the low sunspot years and F layer is very rare now.

A horizontal antenna is better , also, because it is less bothered by local man made electrical noise,.

    At one point back when I was really into VHF, I had a big, Hustler G6-144 vertical and a ten element horizontal Yagi .

Often I would switch antennas just to see how it affected signals.

The SSB ops a hundred miles across the state would disappear when I switched from the Yagi to the vertical.

An FM simplex QSO between mobiles 20 miles away would be solid on the Vertical but get really choppy with the Yagi aimed in their directions.

My Advice is go with a Yagi because you will probably just be working local repeaters on FM anyway !

There used to be dual polarized Vhf & UHF Yagis made but I haven't seen much like this offered lately.

CW is Real Radio 73, John...K8JD


From my electromagnetic fields and waves class in college, polarization is lost after the first ionospheric bounce.

I remember being quite surprised to see that the polarization term, while present in the pre-bounce equation, was gone in the post-bounce equation.

73 Mark K3MSB



My hf vertical antennas are about 4 inches above the ground.

So for skip height not a large factor.

I began on 6m with a horizontal loop configured for coax match.

Taller hanging wires and pvc support for top and bottom.

Yes a vertical loop fed in middle at bottom, hanging as high as I could get it.

Now I use 2 element pvc quad, rotated manually.

At 25 feet high its worked about 30 countries in casual use.

73 curt


Our local club, Genesis Amateur Radio Society, Plymouth, MA, U.S.A. has a net practice that each station in the net calls the recent silent key.


Then each station would call, then the Net Control Station (NCS) would send: NIL HEARD 73 NAME BV SK

    It might be a good practice especially when we have such heavy losses.

About Ben, N6SL, I first met him through the Society of Wireless Pioneers (SOWP) and Slidell Radio/WNU where he worked, and several ships where he was radio officer.

    Along with Dick, K6KSG who sent me the email, he took over the 20m and other SOWP Nets from dear Hank, W1HRQ from Maine who put a large (1 mfd) capacitor in the key line of his Yaesu FT-101, producing a long tail on his Morse so that it sounded like a bell ringing.

    Ben was fairly unique in that he was both an excellent technician and Morse operator, and his reputation was stellar in his field, which I shared, and I shared that fraternal respect, and if he want such generous person, I dare say I'd be jealous, but since he was so generous and loved radio in all its facets, who could not love Ben!

    73 OM BV, you've earned your solid gold Vibroplex!

That's what he used to say and did say when we lost Bob W6BNB a few years ago.

    73, DR David Ring N1EA

Above a notice to the SSNG = SideSwiperNetGroup

Have a nice week, BCNU.
All the very best to you and yours friends, take care!

73, Yann, F5LAW.


REM: I worked Ben N6SL in 2009 twice, may  he rest in peace.


73, your Editor PA3CLQ



My simple website about Gigantic DF-Antennas

Part 1 "DF-Antenna Wullenweber Array"

Part 2 "DF-Antenna USSR Variants"

Part 3 "DF-Antenna USA Variant"

Next Part 4 "USSR OTHRA DUGA 1,2 & 3" at: