R8600 RCA Input on Back of Receiver for Long Wire Antenna?

MTScannerNut

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I have an R8600 receiver on the way and would like to get into shortwave listening. I'm a novice when it comes to shortwave antennas and have been doing a lot of reading and research. I would like to try a "random" or Long wire antenna of about 100-125 ft to see how it performs. I noticed the R8600 has an RCA antenna input on the back listed for Long Wire antennas and is 500 ohm. Would this be the antenna connection I want to use? Or would I be better off using the SO-239 connector instead that is listed as 50 ohm? Thanks in advance, Ed.
 

jazzboypro

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I use the RCA connector but it might not be the best option in my case. I have quite a long run of the wire in the house so it's picking up quite a bit of noise.
 

ridgescan

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Either way is good. I personally chose to use the RCA. My 8600 is in the bedroom at my desk. The feed line for the 100' wire antenna on the roof enters through the wall in the living room. I have an Alpha Delta 2 coax switch there and a 30' coax patch line runs from it to the 8600. I soldered an RCA jack to the 8600 end. It receives every bit as well through this setup as my R75 does which is in the living room very near the feed line entrance.
 

ka3jjz

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If you decide to go this route, do yourself a favor and get the Vibroplex Par EF-SWL antenna (it's widely available). It comes with 45 foot of flex weave for the antenna, but you can substitute it out easily. The connection box has various points where you can change how the balun works with the installation. It will take some experimentation as one setup isn't going to get the same results everywhere.

Just be mindful of where you put the antenna. NEVER run it near power or phone lines and keep it so if it falls, it has no chance of coming in contact with them.

Mike
 

MTScannerNut

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Thanks for all the helpful replies so far.

Maybe I need to start a new thread in the antenna section, but a quick question. Could I run the antenna wire directly from the back of the receiver (no coax) to my wall, then outside? My shack is basically a corner room in my house and the indoor section of wire would be no more than 5-6 feet long. My exterior walls are wood siding with no metal.
 

ka3jjz

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You probably would end up with a lot of noise issues. Getting the feedline and antenna outside and away from the home (and all the noise generators therein) is going to be a key for you. Noise is HF's enemy, and it's not easy to get rid of it all.

Mike
 

WB9YBM

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I have an R8600 receiver on the way and would like to get into shortwave listening.R8600 has an RCA antenna input on the back listed for Long Wire antennas and is 500 ohm. Would this be the antenna connection I want to use? Or would I be better off using the SO-239 connector instead that is listed as 50 ohm? Thanks in advance, Ed.
I've seen stranger connections (everything from 1/8" stereo connectors to a screw on the side of the radio), and they've pretty much all worked. The main things with shortwave antennas are:
  • try to keep them as far as possible from noise sources;
  • keep them as high as possible (old adage: "Height is Might");
  • get as much antenna up as you can; the more you have, the more you increase the capture area for a signal (and at lower frequencies that can add up to quite a bit).
 

ka3jjz

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That third item comes with a bit of a caveat - at some point the radio might overload with MW and other images. Fortunately the reviews tend to state that the 8600 is fairly resistant to overload, If it does, and reducing the RF gain doesn't solve it, a passive preselector or filter will do the job of cleaning up the mess.

If you get longer than say a wavelength at a given frequency you are approaching Beveridge territory - and that's a rather different ballgame

Mike
 

MTScannerNut

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This may be a dumb question:)

If I decide to use the rca connection for my wire antenna, how would I connect the antenna wire to the plug? I’ve found several rca plugs with positive and negative leads attached. Would I just connect to the positive wire and cutoff the negative? Connect to both, or? Thanks again.
 

prcguy

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I would get just an RCA connector and solder your antenna wire to the center pin only. I would also run the wire through an insulator that you can use as a strain relief to keep from pulling and damaging the connector. I would only use the RCA connector for things like camping where the radio is outside away from everything and running on battery power. Otherwise expect a lot of extra noise to be picked up.

This may be a dumb question:)

If I decide to use the rca connection for my wire antenna, how would I connect the antenna wire to the plug? I’ve found several rca plugs with positive and negative leads attached. Would I just connect to the positive wire and cutoff the negative? Connect to both, or? Thanks again.
 

WB9YBM

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If I decide to use the rca connection for my wire antenna, how would I connect the antenna wire to the plug? I’ve found several rca plugs with positive and negative leads attached. Would I just connect to the positive wire and cutoff the negative? Connect to both, or?
What PRCGuy said, plus if you wanted to, you could probably attach the ground of the RCA plug to the ground side of the radios' power supply if that's not already done internally, or station ground...or use it as the second half of a dipole (ground counterpoise)...
 

merlin

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What I would do with a random longwire is use a coupler and input to the SO239.
Receive, a manually tuned coupler will work great. Those automatic jobs take a low power TX at frequency to tune.
Best antenna I used was end fed longwire for SWLing.
 

merlin

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That third item comes with a bit of a caveat - at some point the radio might overload with MW and other images. Fortunately the reviews tend to state that the 8600 is fairly resistant to overload, If it does, and reducing the RF gain doesn't solve it, a passive preselector or filter will do the job of cleaning up the mess.

If you get longer than say a wavelength at a given frequency you are approaching Beveridge territory - and that's a rather different ballgame

Mike
If you really want to get elaborate, consider a preselector. they incorporate band pass filtering, an attenuator and a gain stage. that 8600 has a selctable attenuator, -10, and -20 Db if I recall. Not enough if you have strong AM broadcast nearby. I have -40 Db AM trap and still get some images.
(That 1240 slams me with 50Db with no antenna,,maybe a ball peen hammer to their coax will fix that.)
 

ka3jjz

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Actually not all preselectors have a gain stage. There are 2 basic types - passive (like the MFJ unit) and active (Palomar used to sell these). A passive preselector is a much better bet in areas where urban type interference (MW, FM, TV) can be an issue. An active one is going to be better in a more rural environ where that density is far less, but you want to boost your sensitivity. Many older tube type radios benefit from an active preselector as they tend to drop off in sensitivity the higher in frequency you go.

Mike
 

ka3jjz

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