Using One Antenna for Two Transceivers and Two Scanners

[MotoManDan123]

Hello Everyone,
Rather than trying to explain what I am trying to ask, I prepared a diagram that might make what I am trying to do easier to understand.
I have a TRAM Discone antenna that I have not yet used. I have two transceivers I would like to use to broadcast with the antenna and two scanners I would like to use with the antenna as well. If possible, I would like to monitor all sources simultaneously but obviously, I only intend to broadcast on one transceiver at a time using the one antenna. I prefer not to use an antenna switch but would rather use diplexers for the transceivers to ensure I cause no damage to either one. I would appreciate your thoughts on how I can accomplish what is shown in the diagram and explained briefly above. Thanks very much! MMD

 

[prcguy]

You can but each radio would be limited to one band. If you used a typical triplexer used for public service radios, one radio like the Baofeng could park on VHF only. Then the Uniden could monitor 800 only. Then the Icom 9500 could monitor UHF only off the common antenna and HF from the dipole. Forget the CB on the Discone, even though it claims to cover the CB band it doesn’t work well enough to do it. It there are diplexers that could add the CB to the VHF port from the triplexes.

With the setup described you could unscrew all the coax connectors and move cables and bands around between radios but that defeats your wishes.

 

[MotoManDan123]

You can but each radio would be limited to one band. If you used a typical triplexer used for public service radios, one radio like the Baofeng could park on VHF only. Then the Uniden could monitor 800 only. Then the Icom 9500 could monitor UHF only off the common antenna and HF from the dipole. Forget the CB on the Discone, even though it claims to cover the CB band it doesn’t work well enough to do it. It there are diplexers that could add the CB to the VHF port from the triplexes.

With the setup described you could unscrew all the coax connectors and move cables and bands around between radios but that defeats your wishes.

Hello prcguy! I was not aware there were actually "triplexer's" that could be purchased. This is very helpful. What you described is pretty much what I had in mind but it peaks my curiosity as to why I would have to "park" the scanners on any one frequency? Is there a way I could not have the two scanners running on scan while I'm using the HAM (Baofeng)? I realize while I'm broadcasting on the antenna, I won't get any scan conversations but as I am monitoring a HAM frequency, I'd like to have the scanners running. My intention is to use the antenna mainly for my HAM Baofeng. I see your point on not usin the CB Radio even though I might just monitor it for grins. I do like to monitor the scanners regularly, whether or not I'm having a conversation on the HAM frequencies. Thanks for your expertise and this conversation. Any recommendations on triplexers would be appreciated as well. Thanks again, MMD

 

[prcguy]

Each scanner would have to park on a band but should be able to scan the entire band. Whatever band the Baofeng was on, it could use the whole band like 2m amateur and MURS and monitor anything else in the VHF band. Many companies like Sti-Co, Panorama, Motorola and others make commercial wide band triplexers. Here is one example but it’s way too much $$. I usually pick up Sti-Co and Panorama units off eBay for under $60.

Panorama Antennas Duplexer Triplexer UHF VHF 700/800 MHZ Motorola Repeater | eBay

Find many great new & used options and get the best deals for Panorama Antennas Duplexer Triplexer UHF VHF 700/800 MHZ Motorola Repeater at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[MotoManDan123]

Each scanner would have to park on a band but should be able to scan the entire band. Whatever band the Baofeng was on, it could use the whole band like 2m amateur and MURS and monitor anything else in the VHF band. Many companies like Sti-Co, Panorama, Motorola and others make commercial wide band triplexers. Here is one example but it’s way too much $$. I usually pick up Sti-Co and Panorama units off eBay for under $60.

Panorama Antennas Duplexer Triplexer UHF VHF 700/800 MHZ Motorola Repeater | eBay

Find many great new & used options and get the best deals for Panorama Antennas Duplexer Triplexer UHF VHF 700/800 MHZ Motorola Repeater at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Hello prcguy! Fantastic information Sir and I am VERY grateful for your expertise, advice, counsel, and recommendations on triplexers, particularly in steering me toward those which cost a bit less!! I sincerely appreciate all your advice! MMD

 

[Ubbe]

If that Baofeng are intended for FRS/GMRS at 400MHz, then UHF band will be dedicated to that radio and the CB radio for HF. To not transmit directly into the Icom or Bearcat they will need to have a bandfilter set to VHF and to 800MHz, that you probably just connect the two bands output together and then split to the two receivers.

You will need a quadripler with 4 different bands.

Below 30MHz
50-300MHz
400-500MHz
Above 700MHz

If you skip CB and the VHF airband then that Panorama type of triplexer would be fine.
Duplexers and triplexers usually have only a small 0,5-1,0dB loss.

/Ubbe

 

[MotoManDan123]

If that Baofeng are intended for FRS/GMRS at 400MHz, then UHF band will be dedicated to that radio and the CB radio for HF. To not transmit directly into the Icom or Bearcat they will need to have a bandfilter set to VHF and to 800MHz, that you probably just connect the two bands output together and then split to the two receivers.

You will need a quadripler with 4 different bands.

Below 30MHz
50-300MHz
400-500MHz
Above 700MHz

If you skip CB and the VHF airband then that Panorama type of triplexer would be fine.
Duplexers and triplexers usually have only a small 0,5-1,0dB loss.

/Ubbe

/Ubbe, thank you very much for taking the time to provide your wise expertise on this topic. I appreciate your kind response and you've provided some excellent guidance! Thanks much! MMD

 

[Project25_MASTR]

Another option, though lossy and not really practical, is a control station combiner. There used to be some 100-1000 MHz short haul units available that would let you run 4 transceivers in-band but they had a 15 to 20 dB insertion loss.

 

[jeepsandradios]

Be alot simpler to just put the CCR on one antenna and all recievers on another

 

[MotoManDan123]

Another option, though lossy and not really practical, is a control station combiner. There used to be some 100-1000 MHz short haul units available that would let you run 4 transceivers in-band but they had a 15 to 20 dB insertion loss.

Hello Project25_MASTR! Thanks for commenting on my inquiry and I appreciate your very detailed expert recommendations. I had never heard of a "control station combiner." Even with the loss you commented on, it might be worth a shot! Thanks very much!

 

[mmckenna]

Even with the loss you commented on, it might be worth a shot! Thanks very much!

You need to look at the price and understand just how much signal you'll lose with 15-20dB insertion loss.

 

[Ubbe]

There are hybrid combiners where you can use several transmitters on different frequencies using the same antenna, but as mentioned they have high losses and you can't receive through them in the opposite direction, so will need some kind of duplex filter as well. It would be like a professional setup at a radio site and very expensive.

Those diplexers and triplexers have very low loss and works in both directions but will only allow one frequency band to be used with each radio if there are transmitters involved. Trying to use one antenna for two transmitters with a diplexer and then use only receivers on other antennas will simplify the configuration.

/Ubbe

 

[RRR]

Are you implying you are wanting to transmit into a scanner, on the same antenna?

 

[MotoManDan123]

You need to look at the price and understand just how much signal you'll lose with 15-20dB insertion loss.

Will do mmckenna....thank much!!

 

[G7RUX]

Hello Everyone,
Rather than trying to explain what I am trying to ask, I prepared a diagram that might make what I am trying to do easier to understand.
I have a TRAM Discone antenna that I have not yet used. I have two transceivers I would like to use to broadcast with the antenna and two scanners I would like to use with the antenna as well. If possible, I would like to monitor all sources simultaneously but obviously, I only intend to broadcast on one transceiver at a time using the one antenna. I prefer not to use an antenna switch but would rather use diplexers for the transceivers to ensure I cause no damage to either one. I would appreciate your thoughts on how I can accomplish what is shown in the diagram and explained briefly above. Thanks very much! MMD

View attachment 167143

This looks like somewhat of a minefield.

Whilst you *could* devise a system to allow this to be workable, I would suggest that it will be tricky and expensive and likely give unsatisfactory performance. It would be extremely easy to discover a situation where things do not go at all well and poor performance or damage would possibly result. You will need significant isolation between each of the units, especially where there is a mixture of transmit and receive going on at the same time.

Personally I think I would try to decide on a switching arrangement instead and/or use several antennas.

Using the UV-5 with a linear amplifier is unwise; firstly linear amplifiers are not necessary for FM and secondly the resulting output will likely contain significant amounts of unwanted components.

 

[MotoManDan123]

This looks like somewhat of a minefield.

Whilst you *could* devise a system to allow this to be workable, I would suggest that it will be tricky and expensive and likely give unsatisfactory performance. It would be extremely easy to discover a situation where things do not go at all well and poor performance or damage would possibly result. You will need significant isolation between each of the units, especially where there is a mixture of transmit and receive going on at the same time.

Personally I think I would try to decide on a switching arrangement instead and/or use several antennas.

Using the UV-5 with a linear amplifier is unwise; firstly linear amplifiers are not necessary for FM and secondly the resulting output will likely contain significant amounts of unwanted components.

Hello G7RUX, Thanks much for your expertise and recommendations. I agree with you on the use of the linear amp and have decided to simply by a quality mobile capable car radio that I can put in the car when I want and when I am at home, I can use it as a base station. I intend to use a dedicated mobile antenna for the car and dedicated base station antenna for when I use it at home. I will be using the discone antenna for scanning only going forward. Thank you again for taking a look at my proposal and recommending the switching system! I greatly appreciate the recommendations and your taking the time to give my proposal a look/see! I'm really good at creating "minefields" for myself an appreciate your pointing out that fact! MMD

 

[G7RUX]

Hello G7RUX, Thanks much for your expertise and recommendations. I agree with you on the use of the linear amp and have decided to simply by a quality mobile capable car radio that I can put in the car when I want and when I am at home, I can use it as a base station. I intend to use a dedicated mobile antenna for the car and dedicated base station antenna for when I use it at home. I will be using the discone antenna for scanning only going forward. Thank you again for taking a look at my proposal and recommending the switching system! I greatly appreciate the recommendations and your taking the time to give my proposal a look/see! I'm really good at creating "minefields" for myself an appreciate your pointing out that fact! MMD

Having multiple *receivers* on a single antenna system should be perfectly fine, especially if you can source a decent active multicoupler. Keeping the transceivers separate from the receive system, and from each other is A Very Good Idea(tm) and I would also recommend spacing antennas as far apart as you can manage. If you include some filters to keep signals out of systems they should not be in then you'll get the best performance you can from the kit you have available.

 

[MotoManDan123]

Having multiple *receivers* on a single antenna system should be perfectly fine, especially if you can source a decent active multicoupler. Keeping the transceivers separate from the receive system, and from each other is A Very Good Idea(tm) and I would also recommend spacing antennas as far apart as you can manage. If you include some filters to keep signals out of systems they should not be in then you'll get the best performance you can from the kit you have available.

Hello G7RUX, Once again, thank you for sharing your expertise on this topic, particularly in addressing my having multiple receivers and recommending using a descent multicoupler. Your advice in keeping the transceiver separate from the scanner units is excellent and that was not something I had realistically considered prior to your comments. As for the antenna's, (based on your comments), I thought I would put the discone antenna up on on the back side of the house and the transceiver base station HAM antenna on the opposite side of the house. The discone is "visually" much more noticeable so I would want that one in the back and then the single vertical HAM transceiver antenna (base station antenna) would not be too visually offensive in the front. I plan to use the HAM transceiver antenna here at home when I'm not driving anywhere for a few days but having another similar antenna on my car so I can simply slip in the radio and hit the road. Both the discone and transceiver HAM antenna will be attached to my roof as high as I can safely install them. Bye the way, I do plan to run #10 gauge wire as a ground to an 8 foot copper grounding rod for each antenna so as to provide as much protection as possible from lightning. We get a great deal of lightning here in Florida and want to protect my home and system as much as reasonably possible. In fact, I want the grounding system installed prior to going anywhere near the roof with an antenna in hand as I am a bit paranoid about lightning strikes. It is my understanding more people are killed in Florida from lightning than any other state and I don't want to become a statistic whilst setting up my antenna's. Thanks again for your advice and if you have any recommendations on a multicoupler for the system, I would be very interested in your recommendations. I realize having a separate scanner(s) antenna and HAM radio transceiver antenna, that changes the proposed architecture of my system a bit. However, I still plan to use the ICOM scanner, the Bearcat Scanner, and perhaps scan CB channels (albeit CB appears to be rather useless these days with lots of meaningless chatter but once in a while I hear something informative). Any recommendations on that multicoupler would be appreciated as most of them I look at are designed for television use with the Type F TV coax cable connectors. I could use Type F to SO239/PL256 adapters but prefer a multicoupler with SO239 fittings already installed. Thank you again! MMD

 

[G7RUX]

Hello G7RUX, Once again, thank you for sharing your expertise on this topic, particularly in addressing my having multiple receivers and recommending using a descent multicoupler. Your advice in keeping the transceiver separate from the scanner units is excellent and that was not something I had realistically considered prior to your comments. As for the antenna's, (based on your comments), I thought I would put the discone antenna up on on the back side of the house and the transceiver base station HAM antenna on the opposite side of the house. The discone is "visually" much more noticeable so I would want that one in the back and then the single vertical HAM transceiver antenna (base station antenna) would not be too visually offensive in the front. I plan to use the HAM transceiver antenna here at home when I'm not driving anywhere for a few days but having another similar antenna on my car so I can simply slip in the radio and hit the road. Both the discone and transceiver HAM antenna will be attached to my roof as high as I can safely install them. Bye the way, I do plan to run #10 gauge wire as a ground to an 8 foot copper grounding rod for each antenna so as to provide as much protection as possible from lightning. We get a great deal of lightning here in Florida and want to protect my home and system as much as reasonably possible. In fact, I want the grounding system installed prior to going anywhere near the roof with an antenna in hand as I am a bit paranoid about lightning strikes. It is my understanding more people are killed in Florida from lightning than any other state and I don't want to become a statistic whilst setting up my antenna's. Thanks again for your advice and if you have any recommendations on a multicoupler for the system, I would be very interested in your recommendations. I realize having a separate scanner(s) antenna and HAM radio transceiver antenna, that changes the proposed architecture of my system a bit. However, I still plan to use the ICOM scanner, the Bearcat Scanner, and perhaps scan CB channels (albeit CB appears to be rather useless these days with lots of meaningless chatter but once in a while I hear something informative). Any recommendations on that multicoupler would be appreciated as most of them I look at are designed for television use with the Type F TV coax cable connectors. I could use Type F to SO239/PL256 adapters but prefer a multicoupler with SO239 fittings already installed. Thank you again! MMD

No problems, you are most welcome.

Regards a multicoupler, you could use a CATV/TV distribution amplifier but they can be a bit variable in quality, performance and build quality although they are very reasonably priced. Personally I like the Cross Country Wireless units but they are based in the UK; I am sure there are equivalents available over in the US but I'm not that familiar with the makers there.

Enjoy!

 

[KevinC]

You need to look at the price and understand just how much signal you'll lose with 15-20dB insertion loss.

And the short hauls typically have more like 30 dB of loss…which is why I have a mini stack of them from failed implementations.