ProComm Im-AF Splitter for mobile scanner + CB setup with a single antenna

[VGSMC_8520]

I came across this product, the ProComm Im-AF Splitter CB AM FM Radio Audio Stereo Antenna MultiPlexor, and was wondering if it would allow me to use my 102" whip CB antenna for both my scanner and CB:

http://www.amazon.com/ProComm-Splitter-Stereo-Antenna-MultiPlexor/dp/B00HPH23LA

The antenna coax runs to this unit, and is split at the box to the CB and car AM/FM radio. Somebody correct me if I'm wrong, but I'm assuming this device would attenuate the signal to the car radio when the CB is keyed up, and prevent damage/interference. Would I risk frying my scanner by using this device? I'm looking to improve VHF reception as well as reduce the number of antennas necessary.


Thanks,

Matt

 

[DickH]

I came across this product, the ProComm Im-AF Splitter CB AM FM Radio Audio Stereo Antenna MultiPlexor, and was wondering if it would allow me to use my 102" whip CB antenna for both my scanner and CB:

http://www.amazon.com/ProComm-Splitter-Stereo-Antenna-MultiPlexor/dp/B00HPH23LA

The antenna coax runs to this unit, and is split at the box to the CB and car AM/FM radio. Somebody correct me if I'm wrong, but I'm assuming this device would attenuate the signal to the car radio when the CB is keyed up, and prevent damage/interference. Would I risk frying my scanner by using this device? I'm looking to improve VHF reception as well as reduce the number of antennas necessary.
Thanks, Matt

I would not take the chance and very doubtful it will improve VHF.

 

[VGSMC_8520]

I was referring to the longer antenna improving the VHF reception (using a glass mount antenna currently for the scanner). I would not expect this device itself to improve reception. It seems to have positive reviews on amazon and other sites, so it appears to at least work as advertised on car AM/FM radios ok with no damage.

 

[N8IAA]

As DickH pointed out, using a splitter designed for an AM/FM radio and a CB is dicey. It is meant to be used with the existing AM/FM antenna, and the CB.
Using a transmitter and a scanner connected to the same antenna will cause problems down the road for the scanner. You will only get the benefit of getting a better signal on VHF-Lo Band signals.
To get a better VHF signal, use a mag mount VHF antenna.
Larry

 

[VGSMC_8520]

As DickH pointed out, using a splitter designed for an AM/FM radio and a CB is dicey. It is meant to be used with the existing AM/FM antenna, and the CB.
To get a better VHF signal, use a mag mount VHF antenna.
Larry

Not quite - it's meant to be used with a CB antenna also serving as the AM/FM radio antenna, reducing the need for the factory installed AM/FM antenna. Transmitting on 27 MHz through the factory car stereo antenna is not what the device is meant for. I was hoping to find someone here who has used this and could comment to the validity of all customer reviews on the various sites selling this item which claim it works as advertised with no damage to the car AM/FM stereo.

There's another current discussion on this forum asking a similar question. The user wants to connect a 2m/70cm rig and their scanner to the same antenna:

http://forums.radioreference.com/general-scanning-discussion/299753-duplexers-two-radios.html

This similar product was suggested, and comments indicate it works fine, with the limitation that the same frequency range defined by the low/high pass filters in the diplexer can't be used on both devices at the same time.

MFJ Enterprises Inc. - MFJ-916B 1.8-225, 350-540 MHZ DUPLEXER

 

[DickH]

I was referring to the longer antenna improving the VHF reception (using a glass mount antenna currently for the scanner). I would not expect this device itself to improve reception. It seems to have positive reviews on amazon and other sites, so it appears to at least work as advertised on car AM/FM radios ok with no damage.

The longer antenna might improve the 30 to 50MHz range. For Hi Band (150 to 174) around 18" is the proper length.

 

[N8IAA]

Using a transmitter and a scanner connected to the same antenna will cause problems down the road for the scanner. Larry

You obviously skipped this portion of my post.
I understood that you were looking for a device to allow for transmitting and receiving on two or three separate devices.
Are any of those people advocating the device using it with a CB and scanner?
Larry

 

[N8IAA]

There's another current discussion on this forum asking a similar question. The user wants to connect a 2m/70cm rig and their scanner to the same antenna

And that person will have the same problem with the scanner down the road as you probably will. That person will be transmitting with more power than your CB.
Larry

 

[VGSMC_8520]

You obviously skipped this portion of my post.
I understood that you were looking for a device to allow for transmitting and receiving on two or three separate devices.
Are any of those people advocating the device using it with a CB and scanner?
Larry

lol ok - and you missed the part of my post asking if anybody had any first hand, real world experience with an antenna multiplexer. I appreciate your answers, and your thoughts were also my conclusions before posting. But I was throwing this question out there to see if anybody has anecdotal evidence for/against a setup like I was describing. No, none of the reviews read advocate using with a scanner, but that's why I came here to ask.

 

[N8IAA]

No, I saw that in your post. Didn't skip it That's why the RR community of people who are willing to put their opinions out there to help.
Larry