UHF + UHF Antenna Diplexer

If I've posted to the wrong NG for this then please advise...:)

Does anyone know if there is such a thing as a 'diplexer' for combining two UHF antenna's each pointing in different directions into a single cable prior to being input into an antenna amplifier ?

I have need of 2 x UHF antennas - main one facing north for 4 free-to-air channels & a secondary one facing to the south for a separate single free-to-air channel. Now I can get a 'diplexer' for combining a VHF antenna plus a UHF antenna into a single cable which on taking one apart shows that the VHF side stripline resistive load is different than that used on the UHF side - so NO GO for using such a 'diplexer' when I need to combine 2 x UHF cables together into the one cable feeding into the input of an external aerial amplifier.

Any ideas on what I could do to get this ?

Oz-Rod

If I've posted to the wrong NG for this then please advise...:)

Does anyone know if there is such a thing as a 'diplexer' for combining two UHF antenna's each pointing in different directions into a single cable prior to being input into an antenna amplifier ?

I have need of 2 x UHF antennas - main one facing north for 4 free-to-air channels & a secondary one facing to the south for a separate single free-to-air channel. Now I can get a 'diplexer' for combining a VHF antenna plus a UHF antenna into a single cable which on taking one apart shows that the VHF side stripline resistive load is different than that used on the UHF side - so NO GO for using such a 'diplexer' when I need to combine 2 x UHF cables together into the one cable feeding into the input of an external aerial amplifier.

Any ideas on what I could do to get this ?

Oz-Rod

combining two UHF antenna's each

input into an antenna amplifier

free-to-air channels & a secondary one

I can get a 'diplexer' for

on taking one apart shows that

the UHF side - so NO GO for

together into the one cable feeding

Yep - off the shelf stuff - try Alvin or Hills (assuming you are in OZ)

73 de VK3BFA Andrew

antenna's each

an antenna amplifier

channels & a secondary one

a 'diplexer' for

one apart shows that

side - so NO GO for

one cable feeding

What you need is not a diplexer, which operates on different frequencies, but a simple UHF splitter, as you would use to feed a single antenna to two TVs. This will provide the function you need. A disadvantage is that by combinning antennas you lose most of the anti-interference advantages of the directional nature of antennas.

Still worth a try, though.

d

Pearce Consulting

UHF antenna's each

into an antenna amplifier

channels & a secondary one

get a 'diplexer' for

taking one apart shows that

side - so NO GO for

the one cable feeding

A splitter would lose 3 dB of power on each leg (minus any interference effects). He seems to be saying these are different channels for the different directions. He needs a filter type combining system.

UHF antenna's each

into an antenna amplifier

channels & a secondary one

get a 'diplexer' for

taking one apart shows that

side - so NO GO for

the one cable feeding

If he is trying to combine two similar frequencies, and unwilling to spend tens of thousands on a waveguide combiner, the it is certain he will have as much loss from a diplexer as from a splitter. Anyway, provided the signal is decent on both antenna, 3dB of loss is rarely a problem. I have a 1dB attenuator pad in my antenna cable.

d

Pearce Consulting

UHF antenna's each

into an antenna amplifier

channels & a secondary one

get a 'diplexer' for

taking one apart shows that

UHF side - so NO GO for

the one cable feeding

Oops - make that 10dB.

d

Pearce Consulting

Thanks Andrew. Am considering using a UHF splitter in reverse - hopefully the

3db loss will be compensated for in the masthead amp mounted a few feet below the two antennas.

TIA.

Oz-Rod

Try something called a JoinTenna from ChannelMaster. I bought one from Dow Electronics (google that). You have to specify the channel you are adding. For example, I use a VHF/UHF to pick up all but one station. That other station comes from the oppposite direction, so I have a UHF pointed that way and join it to the other with a channel 10 JoinTenna.

Regards.

the 3db loss will be

antennas.