TV antenna masthead amplifier choice - 24dB or 32dB?

Ooh,

I suspect that he'd get more signal through without the amplifier connected if it's one of the old wide band amplifiers. It's most likely attenuating the signal just by being inline. If it's one of the newer band pass/diplexer type amplifiers I'm amazed he's got any sort of UHF signal through the VHF port!!

I think Johansson make an amplifier that amplifies two UHF feeds, so serves as both diplexer and amp in the one unit.

Sounds like an interesting project. It's shame I'm so far away now or I'd come along and help :)

Cheers,
Iain

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Originally Posted by p38arover

Scouse tells me one antenna (both are UHF) is connected to the UHF input and the other to the VHF input of the present amp. I suspect the UHF antenna on the VHF input isn't getting much signal through. :angel:

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I suspect that you're right on the money. ;) It would be a miracle if it got anything useful through at all.

If you can find a dual input UHF / UHF masthead amp all well and good, or you may install a diplexer before a single input UHF masthead amp to achieve the same end. Either way it's getting a bit more complicated than your average install, professional or learned input is required for a good outcome.

Be very careful if one or more stations are transmitting on the same frequency (same channel) from both towers. Shouldn't happen with adjacent towers but I don't know the area. If this is the case then you definitely need professional help. (Kaye's been telling me this for years :D:D:D).

Deano :)

I'm even further away!

If there is a poor ( say a 15 dBuV or less ) VHF signal present, it is a toss up whether the benefit of using a band stop filter for VHF, to minimise background noise outweighs the insertion loss ( -1 dB ) for the UHF signal.

Aerial design in this instance is important, look for narrow acceptance angle and high rear signal rejection, excessive gain can be controlled by adding a attenuator, which then can be reduced as more outlets are added.

Are both UHF signal sources the same polarity ?
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Originally Posted by wrinklearthur

Are both UHF signal sources the same polarity ?
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Yes. Both horizontal.

This is what I was planning to do some years back, but it changed slightly (not much) - except I no longer distribute the output from the pay TV: http://www.aulro.com/afvb/communicat...und-house.html

The two antennae are still there for off-air transmissions.