UHF or L VHF/ H VHF Signal Combinder? - Page 1
Forum section: electronics / rf-microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 30, 2025, 12:17:15 pm
content: HiI have 2 different Types of Antenna I want combine. A Yagi UHF + a Non Directional UHF and the Second Type is a Lower VHF + a Higher VHF Non Directional Antenna to cover from 80Mhz - 250Mhz everything.Are there some Products on the Market who are affordable? And pls dont come with some normal Splitter the are cancelling signal out.Thanks

author: stretchyman
author_rank: Regular Contributor
timestamp: March 30, 2025, 12:35:02 pm
content: Looks like you may have 3 antennas.You can 'DIPLEX' the vhf & uhf directional antennas and maybe switch the omni in separately?Look for DIPLEXER at a useful crossover frequency.

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 30, 2025, 01:24:00 pm
content: NoUHF Yagi + UHF DirectionalL VHF + U VHFBoth are separated System with there own Splitter and SDR.

author: ftg
author_rank: Frequent Contributor
timestamp: March 31, 2025, 07:41:33 am
content: Cheapest option would be using a power splitter as a combiner.It is not optimal, but it is cheap and easy.But if you don't want to use a splitter, how do you expect the signal to get to you from both antennas?Or all four.Could you draw us a block diagram of what you'd want to happen?Are RF switches not an option for this?

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 31, 2025, 08:00:14 am
content: Its simple there are just 2 Antenna each.UHF Yagi + UHF Omni DirectionalL VHF + U VHF both Omni DirectionalI know there are Antenna Combinder for HF Antenna so I imagine there are such Device for VHF, UHF to.It can be active to no problem with.

author: ftg
author_rank: Frequent Contributor
timestamp: March 31, 2025, 10:18:04 am
content: Active combiners are just power splitters with an amplifier.So this is receive only?For L VHF + U VHF both Omni Directional I'm not sure what you mean? Low band VHF (66-88 or 30+88) and high band band VHF (137 - 174?) you might be able to find a 6m/2m or 4m/2m amateur radio diplex filter. Or some Procom made unit meant for german or swedish police, as those used low VHF and then also other bands.Diamond makes some commercial diplexers and triplexers at a sane price point, but I'm unsure if they fit your usecase.https://www.wimo.com/en/accessories/antenna-accessories/diplexerBut for low powers those are also easy to build yourself.As for the UHF Yagi + UHF Omni Directional, you will have phasing effects regardless if the combiner is active or passive.Both antennas work on the same band, so without a switch both will be receiving.

author: geggi1
author_rank: Frequent Contributor
timestamp: April 01, 2025, 04:31:01 am
content: The simplest is to use a resistive power splitter as a combiner.The Delta configuration is probbably the simplest to build because then you will not need any oddball restistor values.3 50okm reistors will give you a combiner with 6dB loss.If the loss is to high a low gain (about 10dB)preamp can be placed at each antenna to compensate for the coax loss and combiner loss.Preamps must be placed at the antenna to get low noise figures.https://www.microwaves101.com/encyclopedias/resistive-power-splitters