old thing CB coax for antenna connection?

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ModelTrainGeek

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Hi..

I'm just getting back in to really using my old PRO-2021 scanner now. And just put up my little ground plane antenna thats about as old as the scanner itself, also from R/S.

For the lead-in coax I'm use some thin coax that was originally bought for CB use from Radio Shack about 30 years ago Original connector on the antenna end and I've changed the inside one to a Motorola type to fit the scanner. It have been used in the past for out door antennas.

I've been wondering if this cable could be limiting reception since it was original just intended for CB use and this is far higher frequencies now? (VHF/UHF)

I also have some thin ethernet cable from back when I use that for my LAN about 10 or 12 years ago with BNC connectors on it. Would that make a better choice? (once the proper connects have been put on it of course) From what I've seen in the phone book, there's no real scanner dealers around here to ask about this stuff...

thanks :)
 

captclint

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For the lead-in coax I'm use some thin coax that was originally bought for CB use from Radio Shack about 30 years ago I've been wondering if this cable could be limiting reception since it was original just intended for CB use and this is far higher frequencies now? (VHF/UHF)
Thin is probably RG58U. 30 years old is not good either. If it has been outside AT ALL, scrap it.
RG58U is "OK" for runs of less than 50 ft, but RG 6 is much better and not much thicker. Do yourself a favor and get some better cable. It will improve UHF, but much more on 800mhz
Hi..
I also have some thin ethernet cable from back when I use that for my LAN about 10 or 12 years ago with BNC connectors on it. Would that make a better choice?
thanks :)
While cable resistance is not as critical for scanners, I would think this is another questionable choice.
 

kskarma

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Your time is worth something.....

I totally agree about starting out with new cable. If you spend the few dollars needed to get what you need..and RG-6 seems to be a popular choice..then you will never have to wonder if you might be hearing more....or better...or clearer...traffic.

And...since you will be spending a few hours running and connecting this, is saving a few dollars a significant part of the total time spent?

That being said, for using Co-Ax on a scanner (receiver) in most circumstances..local law services, etc..you would be hard pressed to tell the difference in 50 Ohm, 72 Ohm, etc...cables at the generally short distances we are mainly using. Trying to feed an antenna on a 300 foot tower located a quarter of a mile away....a TOTALLY different situation..

Good luck...!
 

kb2vxa

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Yes, scrap all that old cable, but you don't need to spend a fortune for new stuff either. Good old RG6-QS (quad shield) CATV cable and the somewhat larger F connectors it takes are available at Wally World, Home Despot, etc. and you may as well pick up a stripper and crimp tool while you're at it. It's so inexpensive I still have a good portion of a 500' roll left over for future use.

Of course you'll need adapters, they're inexpensive too and available from any on line parts catalog store. Oh, lest I forget a roll of the cheapest vinyl electrical tape you can get will come in handy for waterproofing outdoor connectors. Why the cheap stuff? Premium tape doesn't stretch nearly as well and you need to stretch it and hold tension while wrapping so it lies flat and smooth.
 

ModelTrainGeek

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Thats' why I asked, because I did notice when I was putting the Motorola connector on the other day when I set it up, that the coax's braid was dull and dark now, bot shiny copper any more.

The run is not even 20 feet right now. I'm in an apartment, the antenna is on my balcony just above my satellite dish. (you can hardly even see it from the ground even looking for it) So it's not a huge run. My old pro-2021 only goes to the 400's MHz.. so I won't worry too much about the 800MHz bands until I get a newer scanner. (probably a Uniden with trunking) But that's going to wait a bit til i get working again, got laid off for Christmas.

I already have crimpers for RG6 and RG59 (also RJ11, RJ12 and RJ45, but that's a whole different thing )
I'll take a run over to the local surplus store next week and see what they have in for connectors.. I know they have RG6 in bulk and various connectors, so I just have to see if they have what I need.

I should be able to just solder a Motorola on RG6 for the radio end of the cable. It's converting to a PL259 for the antenna I'll h ave to figure out. For now, I"m run and running even if it's not great it's better then the indoor antenna in a high rise apartment.


Thanks
 

N8IAA

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Thats' why I asked, because I did notice when I was putting the Motorola connector on the other day when I set it up, that the coax's braid was dull and dark now, bot shiny copper any more.

The run is not even 20 feet right now. I'm in an apartment, the antenna is on my balcony just above my satellite dish. (you can hardly even see it from the ground even looking for it) So it's not a huge run. My old pro-2021 only goes to the 400's MHz.. so I won't worry too much about the 800MHz bands until I get a newer scanner. (probably a Uniden with trunking) But that's going to wait a bit til i get working again, got laid off for Christmas.

I already have crimpers for RG6 and RG59 (also RJ11, RJ12 and RJ45, but that's a whole different thing )
I'll take a run over to the local surplus store next week and see what they have in for connectors.. I know they have RG6 in bulk and various connectors, so I just have to see if they have what I need.

I should be able to just solder a Motorola on RG6 for the radio end of the cable. It's converting to a PL259 for the antenna I'll h ave to figure out. For now, I"m run and running even if it's not great it's better then the indoor antenna in a high rise apartment.


Thanks
RS sells PL259/'F' female adapters.
Larry
 

zz0468

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Even 30 years ago, Radio Shack was selling pretty crappy coax. Get rid of it!
 

SCPD

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Get some new coax

... because I did notice when I was putting the Motorola connector on the other day when I set it up, that the coax's braid was dull and dark now, not shiny copper any more ....
Sounds to me like that coax has got wet inside some time or another. Like all have said, coil that up and throw it away. I change all my feedlines every 10 years.
 
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ModelTrainGeek

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Sounds to me like that coax has got wet inside some time or another. Like all have said, coil that up and throw it away. I change all my feedlines every 10 years.

Yes, it's going out soon as I can get to the store to get something to put in it's place.. might wait for a dry day too :roll:
 
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