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 ID this UHF 
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Brought this UHF yagi home from the club to refurb. Its history is unknown, was donated by a SK estate years ago.

Image
Image

Wonder if anyone recognises it as a manufactured article?
Its 18 element, about 12 feet assembled.
The driven element is a 300 ohm loop, and in the grey box appears to be a 4:1 arrangement to present 75 ohms at a N type.
The lead attatched I'm not sure about, too long to be an impedence transformer I'm thinking, so maybe just a N to PL259 bodge lead.

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Fri May 01, 2015 10:13 am
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The feed-point impedance is probably closer to 200 Ohm, so the 4 to 1 BALUN would reduce that to 50 Ohm. It may be a home-brew copy of a Jaybeam?


Fri May 01, 2015 8:09 pm
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Thanks. Difficult to work out if its home brew, hybrid brew or commercial.
The box is a bit bodge but the antenna is well made.
I'm going to straighten it all out and clean it up.
The box lid has 4 holes in it that may have held a badge, else I cant see what else they were for.
I'm told its jolly well old.

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Fri May 01, 2015 9:26 pm
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is it a balun in there? photo useful. insulated thru boom elements. Its prob an NBS design. Anyway just use it.


Sat May 02, 2015 5:05 pm
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I've assembled it in the garage, I reckon its well made home made.
The contents of the box,
Image

and the overall size of the thing.

Image

Tried to get into the only uhf repeater listed in the area with it but no can do.
The only uhf activity I know of is on the isle of wight, so I'll point it that way and leave it scanning.

I'm thinking though its just too big to be useful at home.

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Sat May 02, 2015 5:22 pm
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Well it wont be cut for the fm part of the band althought that wont matter so much.
That type of antenna is usually used for cw/ssb working around 432.200MHz.
The 3db beamwidth will be circa 25degrees.


Sat May 02, 2015 7:04 pm
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driven element looks a lot like an M2


Used to have a huge 2m M2 and its driven element end connector block look very similar

this is modern http://www.m2inc.com/index.php?ax=amateur&pg=136

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Sat May 02, 2015 8:23 pm
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Neill wrote:
driven element looks a lot like an M2


Used to have a huge 2m M2 and its driven element end connector block look very similar

this is modern http://www.m2inc.com/index.php?ax=amateur&pg=136



It does look like it, even down to the way the elements are fixed into the bar.
I've downloaded the spec sheet of the 432-12 will compare the dimensions as a guide

thanks,

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Sat May 02, 2015 8:33 pm
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It looks like an early version of the Vinecom Eagle range.

Ive got a 10 element 2m yagi that uses the same type of construction,those through boom element fixings are a pain as the lockwasher that holds the elements in looses tension over time and the elements slide out.


Sun May 03, 2015 6:54 am
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g4rra wrote:
It looks like an early version of the Vinecom Eagle range.

Ive got a 10 element 2m yagi that uses the same type of construction,those through boom element fixings are a pain as the lockwasher that holds the elements in looses tension over time and the elements slide out.


Agreed, possibly an Eagle.

Almost certainly optimised for the SSB section.

Why not try looking for beacons on it?

Cheers

Tony

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Sun May 03, 2015 9:46 am
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It was mounted vertical though could be drilled for horizontal.
I've tried it into the new Isle of Wight repeater, after setting it up in the clear and at a bit of height, but nothing amazing, no better than my white stick.
At 12 feet long its a bit difficult to mess about with, but another time I'll try horizontal for SSB beacons as suggested.

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Sun May 03, 2015 10:47 am
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G6RRL wrote:
It was mounted vertical though could be drilled for horizontal.
I've tried it into the new Isle of Wight repeater, after setting it up in the clear and at a bit of height, but nothing amazing, no better than my white stick.
At 12 feet long its a bit difficult to mess about with, but another time I'll try horizontal for SSB beacons as suggested.

What does it look like on an analyser?

I'm amazed it's drilled for vertical polarisation mounting. :scratch:
I just can't imagine why that would be.
The mounting pole would need to be an insulated material as well!
Perhaps it's one of a pair of bayed, horizontally polarised, antennas?
Then it would have a horizontal, insulated, crossmember between two of them.

Cheers

Tony

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Sun May 03, 2015 10:55 am
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gw8asd wrote:
What does it look like on an analyser?

Tony


something I really ought to invest in, instead of all these radios

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Sun May 03, 2015 11:18 am
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G6RRL wrote:
gw8asd wrote:
What does it look like on an analyser?

Tony


something I really ought to invest in, instead of all these radios

You could do a sweep, with an SWR meter in line, to get an idea of its resonant frequency.
Do it out in the open and, if you point it vertically you don't need to have it far off the ground.
Obviously, ensure whatever you are using to support it isn't affecting it.

Do it quickly so as not to cause others grief.

Cheers

Tony

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Sun May 03, 2015 4:36 pm
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Nothing at home that will measure UHF, apart from the indication built in the 857 or ts2000.
I'll see what I can come up with from work, may have some slugs for the bird.
TBH, I think this is one antenna I'll be putting back where I found it!

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Sun May 03, 2015 4:58 pm
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