Diamond D-130J Question

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DaveA

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Hello my question is which antenna connector should I get at the base ...... pl-259 or N connector? I will NOT transmit on the D-130J. Which is better? Please list the pro's and con's of each?
 

Junior08

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I just put up a Diamond D130JN Discone. This model has the N connector and was HIGHLY recommended to me due to the fact the PL259 is not very good with higher frequencies, UHF, etc....I am very happy with the antenna so far. Having used Scantennas in the past, this antenna seems to perform just as well, if not better, than the Scantenna especially on UHF. Hope this helps.
 

KT4HX

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I agree, if you have the choice, always go with the N connector. It has a much higher useable frequency range than the PL-259. At the higher freqs you need to minimize your losses whenever you can by using the proper connectors and best quality coax you can afford.
 

BFIFM790

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Question...... when you run the coax from the antenna do you connect it directly to your base scanner or is their some type of device you need to protect the scanner?
 

BFIFM790

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Im sorry...I forgot to ask before...where did you find the Diamond D130J with an N connector every one I see seems to have a PL259. Thank you again!
 

Junior08

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If your going to put this antenna up outdoors, then you will need to ground it. There should be some info regarding that topic somewhere at this site.
 

merlin3rd

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Discone antenna

The Diamond D130JN Discone is one of the best antennas, but with all antennas you should ground them, and always disconnect them from your radios when you are not using them.
 

KT4HX

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Ham Radio Outlet also has the N version. www.hamradio.com In the search bar area in the "Model" box type in D-130NJ. Or go to the "Select by Manufacturer" dropdown box and go to the Diamond Antennas page and scroll down until you find it. Is the same price as the Hamstation mentioned earlier.
 
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What is the ACTUAL loss involved in using an SO-239 instead of an N connector on an antenna used to receive UHF signals at 800 MHZ? All other factors being euqal?

I'll bet it isn't enough to make a difference to the ear.
 

prcguy

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Very little and you or your scanner cannot tell the difference. However if you have a choice, go with the N connector anyway. I have measured the additional loss of PL-259 over N at 500MHz at about .1dB and 800MHz it’s a few 10ths of a dB more. This is using properly installed Amphenol silver plated/Teflon PL-259s. For years, even Motorola used PL-259 jumpers on their high end repeaters and duplexors through 512MHz.
prcguy
 

eorange

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Highlander_821 said:
What is the ACTUAL loss involved in using an SO-239 instead of an N connector on an antenna used to receive UHF signals at 800 MHZ? All other factors being euqal?

I'll bet it isn't enough to make a difference to the ear.
I have the Diamond Discone with the UHF connector, to a 90 foot run of RG-8 mini coax, ending in a PL-259, with the SO-239 to BNC adapter, to my BC780. I can pick up the 800 MHz analog trunked system in the next county with no problems - S7 to 9 on the control channel.

Is it ideal? No. Does it work? Yes.
 

KT4HX

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Personally I don't have the figures in front of me, perhaps someone else does. But the key issue is to make your antenna system as efficient as possible by minimizing losses wherever you can. If a listener is going to the trouble of installing an outdoor antenna and coax, then it's obvious they want to get the best reception they can. Having the correct type of coax connectors is just an extenstion of that thinking. Why spend a lot of money on a scanner and shortchange yourself on the quality of your antenna installation? Will a discone work at 800 MHz with an SO-239 connector - yes. Will it work at peak efficiency - no. That being said, the loss factor of the coax used is more important than the type of connector. The coax will induce more loss as the length increases than the loss associated with a clean, properly installed connector. However, if I have the choice of a UHF or an N connector - I will always take the N connector when it comes to scanning higher frequencies. An added bonus is they create a tighter connection, and thus a better barrier against moisture seeping into the connector's threadings.

This is just one guy's opinion.
 

Junior08

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FWIW,

I am using Times LMR 400 coax with the Diamond Discone, and all bands are received extremely well. If you decide to go with LMR 400, I STRONGLY advise you get it with the connectors preassembled. If you don't know what your doing installing them, you will have serious problems, trust me. I hope this helps.
 

KT4HX

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Couldn't agree more. I have never put connectors on LMR-400, and believe it requires specialized tools to do it correctly. My preference is to buy preassembled cables ready to go at the length I need. When it comes to standard coax, RG-213, 9913, RG-58, RG-59, etc., I will do my own connectors.
 

RISC777

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DaveA,

1. Recommendation - go with the N connector at the antenna end of your feedline (N male), and BNC male at the radio end of the cable. (Put the antenna up as high as you can while keeping the cable run as short as possible.)

2. Ground the mast, if it's metal, not the antenna. (Definitely ground any metal mast!) If you have concern of lightning and such, use an in-line protection device for the feedline. The further precaution(s) are disconnect antenna(s) from the radios and unplug any/all AC power lines.

3. Pre-terminated cable, LMR-400 or/and others are readily available which saves you the job of doing the terminating and they typically will come "certified" and "tested." I order all mine pre-term.d.

Other questions?

`Doug
 

BFIFM790

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I have a couple of questions...

1. Does anyone have suggestions where I can find the pre-made LMR-400 coax cables

2. For connectors, I need a N male to connect to the Diamond D-130NJ?

3. To ground, I was going to set a small screw in the metal mast and run the copper ground wire down from the roof to the grounding rod outside by where my electrical service is...Is that good?

4. With the ground in place...Can I just connect the wire directly from the antenna to my scanner?


Thank you for any input you guys and girls may have
 

STiMULi

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BFIFM790 said:
I have a couple of questions...

3. To ground, I was going to set a small screw in the metal mast and run the copper ground wire down from the roof to the grounding rod outside by where my electrical service is...Is that good?

Do not use an electrical ground as a common ground for your radio(s) / antennae. You may loose in 2 respects.

  • 60hz bleed over from the power grid
  • An electrical hit could be forced into your radios where they would have been otherwise protected.

Keep your antennae grounds as far as reasonably possible from your electrical ground. YMMV and certain situations exclude this rule but for the most part it is the smartest move.
 
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