Got a new mobile 2m/70cm rig for the car

V1Jake

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Swapped out my Larsen tri-band for a Tram 1181 dual band. I want to use my Yaesu now since I'm on the highway for a while and can hit a lot of repeaters

The triple antenna setup looks nice if I had another mount :X
 

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protias

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Swapped out my Larsen tri-band for a Tram 1181 dual band. I want to use my Yaesu now since I'm on the highway for a while and can hit a lot of repeaters

The triple antenna setup looks nice if I had another mount :X
Do you have multiple scanners or are you running an input splitter? I've been wanting an input splitter for years but could never find one.
 

V1Jake

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Do you have multiple scanners or are you running an input splitter? I've been wanting an input splitter for years but could never find one.

Multiple. The 436 with the 5db gain 800mhz antenna and a Yaesu 7900 with the Tram
 

Token

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Do you have multiple scanners or are you running an input splitter? I've been wanting an input splitter for years but could never find one.

What is your goal using a splitter, I mean, what are you wanting to do that you have not been able to?

T!
 

protias

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What is your goal using a splitter, I mean, what are you wanting to do that you have not been able to?

T!
Wideband antennas are taller than I'd like. I would love dedicated low/mid/high band low profile antennas.
 

Token

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Wideband antennas are taller than I'd like. I would love dedicated low/mid/high band low profile antennas.
OK, can you be specific as to the frequency ranges you want covered by different antennas?

And let me get this straight, we are talking about a receive only application, you have one receiver, and you want to attach monoband or individual band lower profile antennas? If I have that right, tell me what bands, specifically, you want broken out.

T!
 

protias

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OK, can you be specific as to the frequency ranges you want covered by different antennas?

And let me get this straight, we are talking about a receive only application, you have one receiver, and you want to attach monoband or individual band lower profile antennas? If I have that right, tell me what bands, specifically, you want broken out.

T!
Yes, 1 scanner, multiple low profile antennas.

I have frequencies from 46 MHz-900 MHZ to deal with here in WI.
 

Token

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Yes, 1 scanner, multiple low profile antennas.

I have frequencies from 46 MHz-900 MHZ to deal with here in WI.

OK, you want more than just power splitters, you also need power splitters that incorporate bandpass filters. Keep in mind that as long as they do not contain active components (pre-amplifiers, etc) such devices are generally bi-directional.

There are many passive splitters on the market, say one to four devices, which can be used to take one antenna to 4 receivers, or the other way around, 4 antennas to one receiver, something like the MiniCircuits ZFSC-4-1-BNC ( https://www.minicircuits.com/WebStore/dashboard.html?model=ZFSC-4-1-BNC+ ).

However, the 4 antenna to one receiver path, with simple power splitters, has a couple of problems. Lets say you have 4 antennas, one (A) is 30 - 100 MHz, one (B) is 100 - 200 MHz, one (C) is 200 - 500 MHz, and the last (D) is 500 - 1000 MHz. The same 162.425 MHz signal hits all 4 antennas, and is passed via the passive splitter. But it arrives at all 4 antennas with a different phase relationship. If it arrives at antenna A and antenna B (B being the desired antenna for that band) at something close to 180 degrees of phase relationship then the signal will tend to cancel itself out, so the net result is a destructive addition (loss) of the signals.

However, if your splitter includes bandpass filters for the desired bands, then the out of phase signals received on A, C, and D would be greatly reduced, and have minimal impact on the signals received in antenna B.

So, you want multiplexers. A combination of splitter and bandpass filter with each port having a defined frequency range.


There is some insertion loss with this, as there is with any passive device. But, it is pretty minimal, and not noticed (although definitely present) in many installations.

Take, for example, the Diamond MX3000 triplexer. It takes a single input (or output) and splits it to three outputs (or inputs), 1.6 - 160 MHz, 350 - 500 MHz, and 850 - 1300 MHz. That could give you three antennas covering those three ranges, but what if you wanted a separate VHF-lo antenna, to cover 46 MHz? Then you could add the Diamond MX62M on the 1.6 - 160 MHz port of the MX3000.

This combination of the MX3000 cascaded with the MX62M would give you 4 ports, 1.6 - 56 MHz, 76 - 160 MHz, 350 - 500 MHz, and 850 - 1300 MHz.

I am not saying that will meet your needs, but you see how by proper selection of multiplexers you can achieve a lot of different combinations.

T!
 

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