AGD horn find

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Albert H
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Re: AGD horn find

Post by Albert H » Tue Oct 01, 2019 5:35 pm

I've got two of those here. I just tried one with an old "modulated regulator" driver across the bench into a "Technomate" LNB feeding a Sharp satcan with a simple AFC tracking control circuit to follow the drifting transmitter! It sounds fine - it's difficult to tell the difference between the source straight to the speakers or through the microwave kit.

The AFC is really crude - the tuning voltage to the satcan is controlled by an LM317, and the reference voltage for the IC is derived from the RSSI (received signal strength indicator) output, so that it always locks on to the centre of the signal.

This gear dates back to 1985. It was built for a west London station, but never used because they relocated their studio and a microwave link became impractical. It's been in my "miscellaneous junk" cupboards for all those years! I forgot I had it until yesterday, and thought I'd dust it down and see if it still works. I might have a use for it in the near future.....
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Bton-FM
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Re: AGD horn find

Post by Bton-FM » Tue Oct 01, 2019 10:22 pm

Are those horns the same ones I’ve got with a flathead tuning screw?

That AFC tracking sounds cool I’ll probably incorporate something like that if I end up using microwave.Also Albert, do you know anywhere to buy satcans from?

Albert H
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Re: AGD horn find

Post by Albert H » Wed Oct 02, 2019 2:35 am

Yes. The horns (like yours) came out of scrapped MVDs (Microwave Vehicle Detectors). They are the ones with the screw head tuning.

Do Sendz Components still exist in Shoeburyness? They used to sell satcans for £3 each.

Try any company that sells old TV parts.
"Why is my rig humming?"
"Because it doesn't know the words!"
;)

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Bton-FM
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Re: AGD horn find

Post by Bton-FM » Wed Oct 02, 2019 4:00 pm

yes they do.They don't have an online shop but you can call them.

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Re: AGD horn find

Post by RF-Head » Wed Oct 02, 2019 10:35 pm


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Bton-FM
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Re: AGD horn find

Post by Bton-FM » Wed Oct 02, 2019 11:22 pm

I saw those but it’s 15£ shipping to the uk!!

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teckniqs
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Re: AGD horn find

Post by teckniqs » Wed Oct 02, 2019 11:55 pm

Bton-FM wrote: Wed Oct 02, 2019 4:00 pm yes they do.They don't have an online shop but you can call them.
That sounds like your best bet then, you won't beat those 1986 prices like that, these days....

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Re: AGD horn find

Post by HamRadioUk » Mon Oct 07, 2019 6:50 am

Bton-FM wrote: Wed Oct 02, 2019 11:22 pm I saw those but it’s 15£ shipping to the uk!!
I have a couple of Sharp satcans for sale as well as c&k horns and two AGD horns with the correct tuning screw.

Couple of link boxs for sale too.

Basically everything you will need.

Message me for prices.

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Bton-FM
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Re: AGD horn find

Post by Bton-FM » Sun Nov 17, 2019 7:40 pm

Sorry to dig up an old thread but is the tuning screw on this horn the hexagonal thing next to the diode terminals or the flathead screw at the back??
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teckniqs
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Re: AGD horn find

Post by teckniqs » Sun Nov 17, 2019 7:48 pm

No :tup

Image

....You are confusing it with the (-) negative Ground terminal connection point.

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Bton-FM
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Re: AGD horn find

Post by Bton-FM » Sun Nov 17, 2019 8:21 pm

Ok thanks teckniqs

Albert H
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Re: AGD horn find

Post by Albert H » Tue Nov 19, 2019 4:12 am

Bton-FM wrote: Sun Nov 17, 2019 7:40 pm Sorry to dig up an old thread but is the tuning screw on this horn the hexagonal thing next to the diode terminals or the flathead screw at the back??
Nope. That's the ground terminal!




That'll teach me! I should have looked for replies!
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"Because it doesn't know the words!"
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Bton-FM
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Re: AGD horn find

Post by Bton-FM » Wed Jul 08, 2020 3:17 pm

Everyone says these horns sound shit but I set one up today and it sounds pucker!

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