RF shielding question...

[kmacka]

I was looking at Ebay and found a guy that sells DX-394's constantly. He puts some sort of rf shielding on the inside of the radio's to cut down on the rf contamination, I think. lol My question is where can you find this type of rf shielding and also is it a good idea to add this type of shielding to my base radio's, even if I don't believe I'm getting interference now? If it is that easy to take off the casing of the radio and then apply a couple strips of the shielding I might as well do it, right?! Is there anything that I have to look out for when doing this?

 

[hypersight]

There is a metallic spray you can buy that you just spray on the inside of the plastic shell of the radio you wish to shield. My father used to have this years ago. I can't remember where you can buy it.......I thought maybe Radio Shack might have had this spray years ago.....but don't quote me on that. You can also check your favorite electronics supply store.

 

[hypersight]

Actually I did a google and found this..... http://www.elexp.com/che_5944.htm

 

[DPD1]

Typically you would want to shield the source, not the device you're trying to protect. The antenna is going to pick up the interference before the actual device does. Unless you have a really serious problem, or the radio is literally sitting on top of the offending device. Unless I'm missing something in your situation.

Simple thin copper sheet can be found at hobby stores. But be careful not to degrade any kind of cooling ability the device needs.

Dave
http://www.dpdproductions.com
- Custom Scanner, Aviation, MURS, GMRS, Marine & Ham Antennas -

 

[iMONITOR]

The late Bill Cheek (of scanner radio fame) used to do this on Radio Shack scanners, such as the PRO-2005, and PRO-2006. I'm not sure if he did it on PRO-2004's. A friend of mine had it done on his PRO-2006 back in the day. I'm not sure how effective it was however.

As Dave mentioned, the antenna will still pick-up the offending interference and bring it into your radio. You may be able to avoid some of that if you're using good shielded coax, ground the radio, and use an outside antenna. It's not uncommon with HF Shortwave radios to have a lot of noise, and static. It's a totally different world from scanners.

 

[kb2vxa]

A word of warning, selection and installation of RF shielding or poking around the insides is NOT for the inexperienced and tectonically incompetent! Remember that smoke is essential for proper operation of electrical components. It is installed at the factory and no replacement smoke is available, if it should escape you'll never get it back in, your radio is fried, you're SOL.

For this and more reasons than can be counted I NEVER trust anyone on eBay, especially that guy Ali Baba.

 

[N4JNW]

I think there is a mod for this radio that involves lining the inside of the case with a layer of aluminum foil. I'm not sure if it work myself, but a fellow ham buddy of mine has a 394, and he took the top cover off to disvoer the mod had been performed.

Not sure if I'd want to do it to mine or not, if I had one. I think I'd rather invest in a good outdoor antenna to help get rid of the interference.

 

[57Bill]

I tried the spray stuff years ago, and wasn't impressed.
Bill Cheek died?

 

[zguy1243]

Shielding the inside of case will help with nearby PC's and computer equipment. If you are still using the radios factory indoor antenna there is no point in doing this mod. As for the DX-394's on ebay, his mods make it sound better on AM but the one that I had was very bassy on SSB, the 394 is a very poor radio to begin with.

 

[iMONITOR]

Bill Cheek died?

Yes, about four years ago. I'm not sure, but I think he had cancer.