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PL 259 Minimum Thread Depth

Printed From: the12volt.com
Forum Name: Cellular and Communications
Forum Discription: Cell Phones, Hands Free Kits, Bluetooth, Two Way Radios, CBs, Pagers, Wireless Internet, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=131441
Printed Date: January 18, 2021 at 1:38 PM


Topic: PL 259 Minimum Thread Depth

Posted By: --weezl--
Subject: PL 259 Minimum Thread Depth
Date Posted: May 19, 2012 at 4:23 PM

SO as some of you know I'm currently installing a ham radio into my truck, I'm working on the antenna right now, and the mounting brackets are taking up much more of the threads than I would like, I've stripped down as many things as I can, I'm now not using the base lock nut, or a plastic washer that holds the aluminum plate off of my truck (factory parts) in order to expose as many threads as possible.

So my question is what is the minimum number of threads needed to make a positive connection between the base of the antenna and the connector?

Even with all of that I am still running low... See pictures for items and threads showing

This is all of the parts, minus the plastic Oem washer

posted_image

This shows the but I decided not to use

posted_image

And this shows the max threads I can expose currently. I can try to grind down that collar somewhat, but it won't give me much more...

posted_image

Thanks in advance!

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Replies:

Posted By: i am an idiot
Date Posted: May 19, 2012 at 8:32 PM

You just need to make sure the center conductor is held all the way in.  You may have to grind some off of the shield part of the antenna to insure that the center conductor is making good contact with the center conductor of the mount.





Posted By: --weezl--
Date Posted: May 20, 2012 at 12:53 AM
How do I know if that is the case though? Lol

I am going to assume it is working, I was listening to a local police department on their frequency, and also the Canadian version of the NOAA weather radio, which came through crystal clear...

The police department I was listening to was about an hour or so away (the city I live in uses an encoded digital system, I was listening to a rural department

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Posted By: js305
Date Posted: September 16, 2012 at 11:50 AM
I know you have likely already solved or made choices but here is my 2 cents worth.

From your other post about impedance I know that in the past car radios used RG62, which, along with being the wrong impedance, is much too small to use for transmitting anything. Yes, it will receive just fine, but the reflected signal will do harm to your transmitter.

As far as the thread length is concerned on the UHF connector you have there you will be fine as long as you have a good center pin connection. In other words, no loose, or barely inserted parts. The location on the vehicle won't matter a lot in your situation. If you were in a real fringe area the rooftop mount is desired for range. To use it like a scanner you will be fine.

Are you going to combine your original AM/FM radio with the ham radio? That's another issue altogether and not really recommended. Again, just for receiving it doesn't matter. Devices used to be made for using the same antenna for a CB radio and the car's radio. They worked, but not well.

Are you sure the two repeaters you are talking about are just five watts? That sounds like CB to me, and not ham.

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Joe in Texas




Posted By: --weezl--
Date Posted: June 20, 2014 at 1:49 AM
js305] wrote:

I know you have likely already solved or made choices but here is my 2 cents worth.

From your other post about impedance I know that in the past car radios used RG62, which, along with being the wrong impedance, is much too small to use for transmitting anything. Yes, it will receive just fine, but the reflected signal will do harm to your transmitter.

As far as the thread length is concerned on the UHF connector you have there you will be fine as long as you have a good center pin connection. In other words, no loose, or barely inserted parts. The location on the vehicle won't matter a lot in your situation. If you were in a real fringe area the rooftop mount is desired for range. To use it like a scanner you will be fine.

Are you going to combine your original AM/FM radio with the ham radio? That's another issue altogether and not really recommended. Again, just for receiving it doesn't matter. Devices used to be made for using the same antenna for a CB radio and the car's radio. They worked, but not well.

Are you sure the two repeaters you are talking about are just five watts? That sounds like CB to me, and not ham.


to reply (long after the fact) yes I got it working, it worked as posted (I think) the wiring was a wire specifically for a ham antenna, not for CB or am/fm, no i'm not using an am/fm antenna of any sort, there's nothing sticking out of the back of my new stereo now. I have no idea what the power of the repeaters I was picking up, was, one was probably around 50w if I had to guess, it's a weather broadcast that you can pickup anywhere in canada, pretty much... there's 5 stations, and you will be able to grab one of them... the other one, IIRC was around 150mhz, so definitely not CB...

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Posted By: catback
Date Posted: July 12, 2014 at 1:04 PM
I'm not sure why your using a UHF connector for an antenna mount. An NMO mount would be the appropriate through-hole mount.




Posted By: ici upfitter
Date Posted: March 13, 2015 at 10:01 PM
I can't say I would have done it that way. I suppose it works but for what you were doing you could have mounted the antenna virtually anywhere on a bracket with the kit you are using. That said, the only important thing in this is if you have the right antenna for the bands you are using, ensuring everything is on par with a watt meter (reflectivity), and a solid ground plane.

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"It's just 12volts...lol!"




Posted By: ici upfitter
Date Posted: July 29, 2018 at 9:52 AM
I am strolling through here and noticed this very old post. I realize from this pictures the mount location you chose is your factory vehicle antenna mount. Stico makes antenna kits for this application that allow you to keep your band for your stock radio and ad on a two way as well. Might want to look into that next time.

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"It's just 12volts...lol!"





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