Antenna Feedpoint Coax Choke

[prcguy]

Ran out of the handy small zip ties.

Same one, both sides.

I’ll keep re-doing this until no one has anything they’d change in what’s seen. Yes, a wrap or two as seen could be tighter.

Comments solicited. View attachment 188547

View attachment 188548

Smaller size zip ties are inbound.

Thx

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Looks much better. But to nitpick, the recommended number of turns to cover CB/10m on an FT-240-61 core is 12 turns and I only see 11. Each time the wire passes through the middle is considered a turn and the cross over is also considered one turn. 12 turns just starts to get really good at about 26.5MHz to well past 30MHz and 11 turns puts the sweet spot at a higher frequency outside the CB band. And leave a little more space between the turns that butt up against the input and output cables.

On Ty-Raps, that's a lot of Ty-Raps. I try to use a pair of Ty-Raps where the cable enters the core, then at each cross over side then where the cable exits the core. After installing the first pair of Ty-Raps at the cable entry point wrap the coax very tightly around the core then hold or tape it while installing the next pair at the cross over so the coax doesn't unwind which allows the minimal number of Ty-Raps to work.

Instead of just one across the cable use two in an X pattern where the cable is trapped through the middle of the X. If you look at really professional installers wiring up racks all the cables are held with a pair of Ty-Raps in an X pattern as I described. If you use just one, which will be at an angle across the cable it will skew the cable sideways where running through the center of an X will run straight through and not pull to one side. And obviously a thinner Ty-Rap would be better, but you used them all up putting almost the whole bag on just one core.

Sorry if I'm coming across as a wise a$$ but I used to train people on how to do these things and this would be a typical conversation with them after doing what you did to a rack in a $100m facility.

 

[slowmover]

Looks much better. But to nitpick, the recommended number of turns to cover CB/10m on an FT-240-61 core is 12 turns and I only see 11. Each time the wire passes through the middle is considered a turn and the cross over is also considered one turn. 12 turns just starts to get really good at about 26.5MHz to well past 30MHz and 11 turns puts the sweet spot at a higher frequency outside the CB band. And leave a little more space between the turns that butt up against the input and output cables.

On Ty-Raps, that's a lot of Ty-Raps. I try to use a pair of Ty-Raps where the cable enters the core, then at each cross over side then where the cable exits the core. After installing the first pair of Ty-Raps at the cable entry point wrap the coax very tightly around the core then hold or tape it while installing the next pair at the cross over so the coax doesn't unwind which allows the minimal number of Ty-Raps to work.

Instead of just one across the cable use two in an X pattern where the cable is trapped through the middle of the X. If you look at really professional installers wiring up racks all the cables are held with a pair of Ty-Raps in an X pattern as I described. If you use just one, which will be at an angle across the cable it will skew the cable sideways where running through the center of an X will run straight through and not pull to one side. And obviously a thinner Ty-Rap would be better, but you used them all up putting almost the whole bag on just one core.

Sorry if I'm coming across as a wise a$$ but I used to train people on how to do these things and this would be a typical conversation with them after doing what you did to a rack in a $100m facility.

It’s what I asked and exactly what I was hoping to receive. Thx!


One thing about Radio which stands out for me is having to learn a discipline and form of patience with myself different than what I’d previously faced.

I’ve had to accept that it will take longer — and that I’ll go thru more supply — than for men for whom these problems are more easily solved. My strengths are elsewhere.

The gratification is high, for me, for Citizen Band as a tool can be right at the heart of something I do well: high-volume integration of information for accurate problem-solving while at speed.

Radio trains ones’ ears. Audio data. High Performance Citizen Band has meant a missing key applied to a lock in real time.

I haven’t expected the men I’ve trained to accomplish the same at the wheel . . . but it’s always a fruitful set of conversations once they see the greater distances to which they must start making decisions and greater number of decisions thereby incumbent. These are already experienced drivers. We discuss Average MPH and Average MPG (derivations of engine hours versus distance and/or fuel consumed). Every foot of roadway matters to lower energy consumption by both vehicle & driver.

The penalties are high for bad habits and for mistakes. “The truck is the job.”


I’ve been impressed with chasing S/NR problems and seen some success . . . as every foot of roadway is time that Best Radio System better utilizes.

The hours I’ll spend on this I already know will get paid-in-full when seconds matter.

The fun may be elsewhere. Goes to morale by getting past mental/emotional fatigue.

And if others learn from my mistakes — like teaching one’s son via the errors of his father —then in my view we fulfill the promise of the hobbyist forum.

I knew I’d be working at this “more” than with what I started.

Thank you, again, Elmer.

.

 

[prcguy]

It’s what I asked and exactly what I was hoping to receive. Thx!


One thing about Radio which stands out for me is having to learn a discipline and form of patience with myself different than what I’d previously faced.

I’ve had to accept that it will take longer — and that I’ll go thru more supply — than for men for whom these problems are more easily solved. My strengths are elsewhere.

The gratification is high, for me, for Citizen Band as a tool can be right at the heart of something I do well: high-volume integration of information for accurate problem-solving while at speed.

Radio trains ones’ ears. Audio data. High Performance Citizen Band has meant a missing key applied to a lock in real time.

I haven’t expected the men I’ve trained to accomplish the same at the wheel . . . but it’s always a fruitful set of conversations once they see the greater distances to which they must start making decisions and greater number of decisions thereby incumbent. These are already experienced drivers. We discuss Average MPH and Average MPG (derivations of engine hours versus distance and/or fuel consumed). Every foot of roadway matters to lower energy consumption by both vehicle & driver.

The penalties are high for bad habits and for mistakes. “The truck is the job.”


I’ve been impressed with chasing S/NR problems and seen some success . . . as every foot of roadway is time that Best Radio System better utilizes.

The hours I’ll spend on this I already know will get paid-in-full when seconds matter.

The fun may be elsewhere. Goes to morale by getting past mental/emotional fatigue.

And if others learn from my mistakes — like teaching one’s son via the errors of his father —then in my view we fulfill the promise of the hobbyist forum.

I knew I’d be working at this “more” than with what I started.

Thank you, again, Elmer.

.

I'm happy if you can make use of any information I share but when someone calls me Elmer, I think of the Looney Tunes character with a shotgun chasing a wabbit. Not sure I wanna be that guy.

 

[slowmover]

I'm happy if you can make use of any information I share but when someone calls me Elmer, I think of the Looney Tunes character with a shotgun chasing a wabbit. Not sure I wanna be that guy.

Well, you know the history of the term: meant as compliment.

Past my misinterpretation of how to wind the thing (using zip-ties to separate windings), my further misinterpretation of using (11) versus (12) windings to get better-centered in useful range given RG316 vs RG58.




DIY has pitfalls. But can’t fit a boxed choke under headliner.


Found another useful image at local-to-me Balun Designs where the linked description benefit of Noise Reduction for resonant vertical antennas already with low SWR is well-done.



1). Treat both ends of coax;
2). Ground shield at some point in run.
(re-read a QRZ thread per WA7ARK)

That follows my big truck experience where the transceiver has a MYANTENNAS filter directly attached and, in turn, the shield is grounded by use of a MORGAN 411cn BPF just downstream. The level of quiet became astounding (my experience is mobile-only).

Faster uptake of data per faster reaction to queries by other mobile operators (Clarity of TX). No lag time.

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[slowmover]

@prcguy 12T ft240-61
Note orientation of all.




Haven’t been up to store to get more small zip-ties. Decided to re-do anyway, and did.

Have been having an SWR problem since starting this. This story being told as being new in CB can be frustrating. I swapped (6) pieces coax, (3) radios and (2) mics. Almost took antenna mount off after finding nothing wrong with antenna.

— Dont mix good coax with damaged. I did that somewhere along the way.

Back to Coax Choke: despite care had a connector come off the new RF316 jumper. Sometimes you have to ask, “what does this mean?” Since this assembly was slated to go under headliner against bare metal roof — and there are cautions about keeping such 2-3” away from metal — I decided it’s best to leave to another day.

The bright note was a second dial-in of the PRESIDENT Lincoln II+ V.2 once PALOMAR chokes back in line having found the earlier coax jumper assembly (a good one).

This time had a spare radio in back seat (no coax) and listened to myself across the air. Stock mic fine once Mic Gain adjusted. The DIGI-Mic I’d spilled coffee on awhile back. Wasn’t sure if I also hadn’t pulled too hard on cord (use a mic hanger so microphone never “falls”). Used contact cleaner and put it aside as was getting reports I didn’t sound right on air.

Well, once decision made to leave thread subject alone it all started working right again.

Go figure.

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[slowmover]

Ha!

Just made a contact from down-in-the-hole where I’m living. That’s xtra rare at 1500 with some Skip.


Other experiment:

A). Have a generic, “Lightning Arrestor” at back of radio. Ground wire run to 12V distribution block.





B). And this 400k mile road dog near antenna feedpoint:



— Coax shield grounded at both ends plus choke at feedpoint —

Lincoln II & Texas 1800.
Digi-mic + W-M speaker.
(RX & TX w/DSP)

— Last, squared-away the radio rig atop center armrest console (good thru Labor Day). Need to run-up a four or five device RF Bond harness, next.


Getting a response @ 12W of, “It’s working, driver”, I’ll take as confirmation that system is okay for now.

Those crayons @jcrmadden passed my way musta had a little somethin’ in ‘em.

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[slowmover]

Use of a choke

Impedence matching to cb radio

Hello, I'm thinking of installing some co-phased RG-59 A/U into my cb radio in my big rig. Since RG-59 is 75 ohms or 72ohms and the SO-239 connector on the radio is 50 ohm impedence, I was wondering what the best way might be to match the antenna and coax impedence to the input of the cb...

forums.radioreference.com

Co-phase

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