| InterceptRadio.com Forums http://interceptradio.com/bbs/ |
|
| One antenna, multiple scanners http://interceptradio.com/bbs/viewtopic.php?f=1&t=2270 |
Page 1 of 1 |
| Author: | nickcarr [ Mon Aug 18, 2008 6:43 pm ] |
| Post subject: | One antenna, multiple scanners |
Guys, I'm having trouble finding something. Can anyone recommend a product that will let multiple scanners feed into one antenna. I'd preferably like it to be full-time (i.e. no selector switch)... is this possible? Some questions: 1. I take it a device like this would be receiving only or is transmitting possible? 2. Would I need any kind of pre-amp to boost the antenna signal before going into the switch? 3. Right now, I'm only talking concerned about VHF or higher (50mhz+)... but does this exist for HF as well(< 30mhz)? Thanks -Nick |
|
| Author: | SpudGunMan [ Mon Aug 18, 2008 7:40 pm ] |
| Post subject: | Re: One antenna, multiple scanners |
you can just use a splitter, like a BNC distro block for full bandwidth. When your Rx you dont need to worry, if your going to Tx you would want a auto switch or a real switch having your Rx only equipment on the same switch as Tx might cause damage if the switch has no protection. |
|
| Author: | Mark [ Mon Aug 18, 2008 8:52 pm ] |
| Post subject: | Re: One antenna, multiple scanners |
http://www.tti-plus.com/Cables-Connecto ... mClick=540 Top right. I use it all the time both in my car and at home. Male goes to the back of my mobile scanner, antenna to one of the females and a 3 foot male-male to the other female. In the old days I did get some interaction between the two radios, but not with the newer scanners. I currently use a 780 and 396 together. I don't know much about the inside of radios - OK nothing - so I'm sure someone that can measure whatever you 'inside radio' types measure and say 'no you loose 1/2 of your signal'.... Whatever, seems to work for me - DOES seem to effect 800 in a negative way. |
|
| Author: | N7QOR [ Mon Aug 18, 2008 9:16 pm ] |
| Post subject: | Re: One antenna, multiple scanners |
The "Splitters" referred to above are a better way to go, as using a BNC "T" can alter the impedance in each receiver at the first stage. Some scanners may be OK with this, but when I tried it with commercial radios programmed to scan (receive only) it made each radio quite deaf. I have used the full bandwidth splitters you use for CATV, although I think those are set for 62-75 ohms (as opposed to 50 ohm for typical radio applications) Still, even being off impedance a bit, it worked better for me than a T. I will have to try it with some newer scanners though, I haven't tried in a long time and it sounds like the newer scanners are more resilient. 73, Nick N7QOR |
|
| Author: | Atomic Taco [ Mon Aug 18, 2008 9:58 pm ] |
| Post subject: | Re: One antenna, multiple scanners |
ScannerMaster makes Radio Shack look cheap. |
|
| Author: | Rich [ Tue Aug 19, 2008 7:07 am ] |
| Post subject: | Re: One antenna, multiple scanners |
Theres no need to use an overpriced multicoupler for your application. Run some good-quality RG-6 (i.e. CommScope or Belden) with decent fittings and a cable tv splitter. This will do the job. Now I know some people will scream bloody murder over 50-ohm vs. 75-ohm however the reality is that the difference in receive performance is negligible. Been there, done that, and actually measured it. As Nick said, it works better than a "T" fitting. Two caveats; don't transmit through it and don't expect it to work very well at HF frequencies. |
|
| Author: | MTM [ Tue Aug 19, 2008 9:33 am ] |
| Post subject: | Re: One antenna, multiple scanners |
I'm with Rich on this one. I use an 8 port TV cable splitter -- 5 to 1000 Mhz -- from Home depot -- $ 17.00. Works just fine -- in the Metro areas. |
|
| Author: | Mark [ Tue Aug 19, 2008 9:57 am ] |
| Post subject: | Re: One antenna, multiple scanners |
How does F win over BNC? |
|
| Author: | MTM [ Tue Aug 19, 2008 10:12 am ] |
| Post subject: | Re: One antenna, multiple scanners |
I bought cable with F connectors on one end and BNC on the other. Works great. If you live in the city -- it work just fine. If you live 50 to 75 miles away -- you might have some signal loss problems. It all depends on what your'e listening to. |
|
| Author: | Rich [ Tue Aug 19, 2008 11:17 am ] |
| Post subject: | Re: One antenna, multiple scanners |
MTM wrote: I'm with Rich on this one. I use an 8 port TV cable splitter -- 5 to 1000 Mhz -- from Home depot -- $ 17.00. Works just fine -- in the Metro areas. Agreed... if you have 8 radios ! In best-case scenario, try not to use a splitter bigger than what you need.... 2-way splitter = 3.5 db loss 4-way splitter = 8 db loss 8-way splitter = 11 db loss Though in fairness a few dB of additional losses isn't the end of the world if you are listening to local repeaters or trunked systems. |
|
| Author: | MTM [ Tue Aug 19, 2008 12:00 pm ] |
| Post subject: | Re: One antenna, multiple scanners |
50 % or more of the group -- most likely live in the Metro Seatle-Tacoma-Everett-Bremerton areas. Since 75% are listening to 800 Mhz trunked systems, there should be enough signal to over-come any losses. It will work for most. |
|
| Author: | chpalmer [ Tue Aug 19, 2008 4:07 pm ] |
| Post subject: | Re: One antenna, multiple scanners |
Having a mismatch with impedance is not going to hurt the receiver so what ever works for you. http://www.google.com/search?hl=en&q=re ... tnG=Search :D |
|
| Page 1 of 1 | All times are UTC - 8 hours |
| Copyright © 2013 Interceptradio.com |
|