Reception problems - I'm stumped!!

[ronmchandler]

I continue to have a problem with my Pro-2096 in the VHF Hi band, 150's. In my shack, I have the 2096 sitting on top of a Uniden scanner and next to two Icoms. My PC sits under the desk with an LCD monitor on top. I'm using a discone antenna. Assuming a front end overload, i have tried using an FM Trap, attenuation, and anything else I could gather from advice and suggestions, to no avail. Last night I disconnected my discone and moved the 2096 across the room to a bookcase and installed the stock antenna, and, UREKA!!, it began to pick up the freqs it has previously ignored. I then took my Pro-96 handheld, which receives VHF Hi band very well and moved it to the desk where the 2096 was sitting and it went deaf on VHF Hi too, just like the 2096. Even when both are hooked up to the exterior discone, both radios become silent when sitting on the desk. Rubber duckie, stock antenna, exterior discone.....nothing makes any difference.

Question is, what is it about that desktop location that is silencing those frequencies. I powered down the computer and everything else, and the scanner was still silent sitting on the desk? Is it something else? Any suggestions? The Uniden (780xlt) works great sitting in the same location.

 

[ksmoscanner]

If it only happens when hooked to the discone I would check for a possible short in the coax? Check the center pin to shield for continuity. You should have none.

Gregg

 

[ronmchandler]

The discone makes no difference. Even the Pro-96 with the rubber duck attached which works well across the room goes silent in the 150's when put on the desktop location.

 

[mancow]

Do you happen to have a Linksys router in the area?

They are horrid when it comes to RF interference, especially Vhf. I found the non wireless version to be the worst. Maybe the wireless versions are shielded a bit better.

Otherwise it's probably some PC component. I found that coiling up the extra length in the Cat5 cable helped to cut down on the interference.


mancow

 

[djeplett]

Ethernet alone can be very noisy. It got so bad for me that I've switched to wireless so I can move my router and hubs elsewhere in the house. Oh, and the brand of my router is D-Link.

 

[FPO703]

I also have problems when hooking my PRO-96 up to my discone antenna. However, if I turn the ATT on, it pulls in signals from all corners of the planet. Go figure. Same thing with my PRO-92

 

[jim202]

You might try unpluging all the computer related power cords. Some computers are still on even thogh you have shut them down software wise. The poser supplies stay up and some of the circuits. Humor yourself and pull all the plugs.

Test your reeceiver. If it works, then plug one device at a time back in.

Jim

 

[djeplett]

Along the same lines, if you do have anything ethernet, just unplugging the ethernet cables from everything didn't solve my noise issues. Unplug from your wall outlets all hubs, routers, cable modems, etc. That's how I found out my router and hub were the noise generators. Even with all the cat5 cables removed I still had a ton of noise.

 

[kb5udf]

Ditto w/ethernet

My motorola cable router puts out so much rf across the cat-5 cable,
that depending on how near the radio/coax is to the cat-5, it opens up the squelch even at the highest setting.

It may be my imagination but rolling some (cat-5) to make a loop seems to have helped. ALso, I was able to move the cable modem about 7 or so feet away from radios which also seemed to help.

 

[MacombMonitor]

How about leaky cable TV?

 

[mancow]

I've had the leaky cable tv issue in the past but it always seemed to be easier to identify due to the characteristic video hum and overmodulated audio signals.

The ethernet interference was horrid. It would open the squelch on the radio in another room through two walls.


mancow

 

[ronmchandler]

Problem solved!! I tried one last thing today. I went by Radio Shack and picked up the little 20-176 VHF-Hi/UHF antenna and mounted it in my 3rd floor attic. Hooked it up to the 2096 and immediately saw the "deaf channels" start appearing. The 2096 now matches reception with the Uniden 780 sitting next to it on VHF-hi.

The outdoor discone antenna just WAS NOT a good match on VHF-Hi for the 2096. However, this little antenna only performs well up to about 500 mhz. It is very weak on 800 mhz. That's where the discone is stronger.

So, I've learned alot in the process of working through this problem.

 

[MacombMonitor]

So it must still be related to getting the antenna out of your room, that made the difference. What did you use for coax? Running that lenght of coax could explain the poor performance in the 800MHz band, due to signal loss in the cable.

It would still be interesting to track down what the real problem was. Maybe you should start searching ranges of frequencies in the 150MHz band, and see if you find a strong source of interference.

 

[N_Jay]

I also have problems when hooking my PRO-96 up to my discone antenna. However, if I turn the ATT on, it pulls in signals from all corners of the planet. Go figure. Same thing with my PRO-92

Classic overload.

How far are you from the nearest FM, TV or communications tower?

 

[brwkem]

Will putting an antenna and hooking up to a portable help with the RF interference in a room with multiple pc's lcd's and other electronics?

Room I have portables in reception is terrible .

thx