UHF VHF splitter

[Halifax Sailor]

Picked up a new in package UHF/VHF splitter. My vhf antennae is top of mast, my stereo antennae is under the cockpit. Thinking that if these splitters work would get great reception while cruising with the boat. Has anyone used these? and do they work? only paid $5 cdn (thats about 50 cents US funds) so no big loss if it doesn't work.

[sv_pelagia]

Originally Posted by Halifax Sailor

Picked up a new in package UHF/VHF splitter. My vhf antennae is top of mast, my stereo antennae is under the cockpit. Thinking that if these splitters work would get great reception while cruising with the boat. Has anyone used these? and do they work? only paid $5 cdn (thats about 50 cents US funds) so no big loss if it doesn't work.

Never worked for us.

[skipmac]

Have used splitters for years for exactly this reason but had some concerns. They do work. I was able to receive FM stereo from the masthead VHF antenna and pick up stations many miles away. BUT I wondered how much the splitter might attenuate the VHF signal, both sending and receiving.

Discussed with some radio and antenna experts and the opinion was, depends. In this case you usually get what you pay for. A high quality splitter will introduce very little loss but a cheapo probably a lot.

Also, if this is a manual splitter you have to remember to switch it from stereo to VHF before transmitting or you could fry the VHF.

Better option, again recommended by knowledgeable radio people, I got the Vesper active splitter. It requires power and is not cheap but it automatically switches between units, has connections for VHF, stereo and AIS. Had this for a couple of years now and works perfectly.

[continuouswave]

Originally Posted by Halifax Sailor

[purchased] a UHF/VHF splitter.

There are no marine radio services authorized in the UHF spectrum for non-government ships, so I doubt there is any application for the device you purchased. Or, perhaps you have used the acronym UHF in error.

[skipmac]

Originally Posted by continuouswave

There are no marine radio services authorized in the UHF spectrum for non-government ships, so I doubt there is any application for the device you purchased. Or, perhaps you have used the acronym UHF in error.

I assumed from the OP that the splitter was rated for UHF and VHF but he was buying just for marine VHF and FM stereo use on his boat since, as you point out, there are no UHF applications for recreational boaters.

[continuouswave]

Originally Posted by skipmac

I assumed from the OP...

I assumed that a device called a VHF/UHF splitter would provide some sort splitting of signals in which it accepted signals of both VHF and UHF on one port, then filtered the signals so that on a second port only VHF signals would be present and on a third port only UHF signals would be present. I came to that assumption based on the meaning of the term "split" and the concept that the only difference in the signals would be the range of their frequencies, with VHF being 30 to 300-MHz and UHF being 300 to 3,000-MHz.

If the device performed in the opposite manner, that is, if it combined UHF and VHF signals from two separate input ports to a third output port, it would be called a combiner.

Regarding the inference made by others that the device was to be used to provide a s signal for an FM Broadcast Band radio from a VHF Marine Band antenna, both the FM Broadcast service and the VHF Marine service are in the VHF band.

[wholybee]

If it is the device that I think it is, especially given the cheap price, it is the VHF/UHF splitter used to connect a single TV antenna to 2 television sets. Unless you have a TV antenna, and 2 TV's on your boat, it won't work well for anything else.

If connected to your VHF radio and an FM radio, you will attenuate your VHF signal 3db, and probably overload and fry your FM radio as soon as you transmit. As long as you never transmit on the VHF, it might otherwise work ok if you can live with the 3db loss.

That is assuming it is what I think it is. Maybe it is something else.

[Brian.D]

Splitter and Combiner are engineering terms solely for the use of knowledgeable RF folks. For the layperson, the term is interchangeable, meaning, not to confuse a layperson with two terms when one term, splitter, can be used regardless if you have one antenna for two radios or one radio for two antennas.

In this case with the OP, we are getting into semantics and falling down a deep rabbit hole. It appears the intent of the OP is to listen to FM radio with his VHF antenna while cruising.

[S/V Illusion]

You should verify what the attenuation is between sides in the splitter. Anything lower than 60dB can cause the standby radio to be overloaded.

The other caution is that splitters fail and you won’t know when until it’s too late.

[skipmac]

Originally Posted by Brian.D

Splitter and Combiner are engineering terms solely for the use of knowledgeable RF folks. For the layperson, the term is interchangeable, meaning, not to confuse a layperson with two terms when one term, splitter, can be used regardless if you have one antenna for two radios or one radio for two antennas.

In this case with the OP, we are getting into semantics and falling down a deep rabbit hole. It appears the intent of the OP is to listen to FM radio with his VHF antenna while cruising.

Exactly, these can work both ways. And I am pretty sure that the OP is trying to use his VHF masthead antenna to feed his FM stereo so he would use it in the one antenna to two radio mode.

A good quality, manually switchable splitter can do this safely and with little signal attenuation but the operative words are good quality.

[Hartleyg]

There are a number of devices that meet the label:"VHF/UHF Splitter", but the only ones that would normally hit the price you mention are for television receivers. Leaving aside the uselessness of the UHF side to FM Stereo reception, these TV devices will melt if you apply 25 watts of VHF power from your radio.
Post a picture (or make/model) of the device you bought and you will probably get more relevant advice

[skipmac]

Originally Posted by Hartleyg

There are a number of devices that meet the label:"VHF/UHF Splitter", but the only ones that would normally hit the price you mention are for television receivers. Leaving aside the uselessness of the UHF side to FM Stereo reception, these TV devices will melt if you apply 25 watts of VHF power from your radio.
Post a picture (or make/model) of the device you bought and you will probably get more relevant advice

I would guess the same as well, based on the price and label of UHF/VHF splitter. Could be totally unsuitable for marine VHF.

[Jammer]

I'm not sure I understand what you're trying to do.

If you want to use your marine VHF antenna to receive broadcast FM stereo transmissions, it will work OK and probably be an improvement. Just plug the marine VHF antenna into your FM stereo, using or making an adapter if necessary. You will not be able to use your marine VHF radio at the same time. Even if you connected them both, the power from the transmitter on the marine VHF radio would damage the stereo.


Splitters designed for television use will not help. The VHF television band covers a wide range and overlaps with both broadcast FM radio and marine VHF, so the television-oriented splitter will not actually separate these three signals.


FM broadcast uses VHF. The VHF band extends from around 50 MHz to around 216 MHz with the exact boundaries depending on context. Broadcast FM is 88-108 MHz and the marine band is 156-162 MHz.

[Halifax Sailor]

I may have mis-spoke, the package reads am/fm-vhf splitter. It has connections for stereo and vhf radio and on the other side the connection for the vhf antennae at the top of the mast. It says "...can be used at same time, no issue with either radio...". However, being the cautious guy that I am, just wondering if anyone had used such a thing?

[Hartleyg]

That device will work for what you want. I've used the Shakespeare version on my boat for many years, and it does function satisfactorily. I suspect an actual dedicated masthead FM antenna might work best, but the VHF side will be fine and it will work for the FM side much better than one of those below-decks antennas.