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Mike-CT
05-10-2011, 01:34 AM
This antenna was made entirely from an old Channel Master Stereo Probe 9.

It's cut for 48mhz but has a parasitic element directly under the driven element to widen the bandwidth. That must be working because it seems as good as my Winegard PR-5030 on ch2 and 3.

The elements on the Probe were too short for 48mhz so I had to "splice" sections together to get the proper length. What I did was cut 4" pieces of element. Then I spread them out with a large screwdriver along the seam. This made the inside diameter wider and I was able to hammer the sections into the 4" splice to make one long element. Then I took some heavy aluminum ground wire and wrapped a few turns around the splice for added security. The ground wire was probably overkill as the splices really hold the element sections tight.

The plans came from the K7MEM website (http://www.k7mem.150m.com/Electronic_Notebook/antennas/yagi_vhf.html#Freq_BL).

The reflector is 120 11/16" total length.
The driven element is 119 5/8" long.
The director is 111 11/16" long

Spacing from the reflector to the driven element is 49 3/16".
Spacing from the driven element to the director is 65 3/16".

The element under the driven element is 4 feet, 3 1/16"(each side).

All the aluminum is 3/8".

Gain is estimated at about 4.7db which is 4.7db more than anything else I've ever used here for E2.

We will see what results I get with this and a D-100. Hoping for some RTP video and some R1 video carriers at least. Spring should be interesting.

mrhoover
05-10-2011, 03:15 AM
Looks great Mike,hope the signals come in soon.Certainly will give you much more signal than N American lowband TV antennas that drop off in gain below 55.25 MHz.

Cheers

Hugh

tvdxrools
05-10-2011, 04:10 AM
good stuff mike .. finally a dxer over your way will be actually looking for EU tv .. cheers david

Danny
05-10-2011, 04:13 PM
Mike, best of luck using the antenna. It looks like you did a good job with the construction.

NN2E
05-10-2011, 05:16 PM
Good deal, Mike. I hope you find some Euro DX before they're all gone.

FWIW...I use small hose clamps to fasten the "tubing" sections together. I've got a couple of splices in the Finco P-7 fastened that way. Of course, now that your antenna is in the air, your response would be something like..."Now he tells me." :-)

73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

pjdyer
05-10-2011, 06:56 PM
That looks a lot like the 3-el 6m beam that K5DSF gave me in early 1964. He was an electrician so it was made of steel conduit (HEAVY) - I never really installed it (parted with it in early 1966). My home-brew 3-el 15m Yagi is made up from various dia aluminum tubing with plenty of hose clamps to keep them together.

73, Pat - WA5IYX

cd637299
05-10-2011, 07:10 PM
Mike, I need to PM you later....I can't build anything like you have, but I need some pointers.

cd

Gary Hickerson
05-10-2011, 08:28 PM
Mike,

Looks great. What is the total boom, lenght? How high abg, is it? Are you taking, any Orders, for this ? ? ?

Gary H.
Okla.

Mike-CT
05-11-2011, 12:09 AM
Gary...
Boom length about 118 inches. About 25feet AGL.. Taking orders,lol ??? I'm all out of junker antennas to use.
BTW it does work on ch 10 & 11. No problem with WWLP-DT. WTNH-DT 10 (50mi) can be watched but I have to use a preamp.

Can a VHF amp be used with this antenna or does the amp gain drop off the cliff as soon as the freq goes below 55mhz ?

I had a surprise when I took down the Winegard VHF. All the rivets that hold down the elements were rusted out. Six elements are connected in a criss-cross type of feed design and I checked for continuity all along the way. On one side I lost it directly behind the driven element. I'm surprised it worked at all. I bridged the break with some heavy aluminum guy wire but I think I'll have to buy a new antenna. Maybe just a high band model this time. Not sure yet.

mrhoover
05-11-2011, 06:04 AM
Gary...
Can a VHF amp be used with this antenna or does the amp gain drop off the cliff as soon as the freq goes below 55mhz ?

You'll have to test that one on a 50 MHz beacon which maybe you have within non skip range and anything else in 46 47 48 49 MHz range to use as a reference.You really only want a preamp just to make good the loss of the split if you're feeding the D100 and radio.

Hugh

Gary Hickerson
05-11-2011, 02:33 PM
Mike,
From what I've found out, so far, a VHF preamp covers from 50 - 300 mhz. Haven't seen a graph, to know how steep, the fall off, is ! If I find more info, I'll send it to you.

Gary H.

mrhoover
05-11-2011, 03:31 PM
There's a well known "printed you know where" sticker on RF splitters amps etc in Eu that says 50 to 300 50 to 1000 etc,despite E2 vision carrier being at 48.25 MHz,usually the response doesn't drop at 50,though maybe some types for your market may filter out the ham band to keep Ch A2 clear,

Hugh