Cobra 18 WX ST II (don’t laugh)

[ForestRunner98]

Thanks for all your help Andy! I gave it the college try. Ya that bonding was magic! Would have thought a 98 4Runner was better grounded. It sounded so nice with just the inner conductor plugged. Signal and radio chatter were so clean! I think I will try the Palomar filter as a final battle with this war on noise. The pic I posted of the filter is correct for CB yes? Don’t want to blow $60 and have it be wrong. At least this thread could possibly help some other lost soul like me. LOL

 

[Handy Andy]

Just keep it (install it) between the RADIO and the AMP - let us know how it works out for you!?

 

[Slowmover]

For my own endeavors:

1). Install Coax Filter at receiver end of coax cable.

2). Antenna feed-point needs an RF/CMC Choke at other end of coax.

Same vendor (Palomar) has several.
(I also buy ferrites there).
Not only supplier of such devices.
DIY, and on upwards in price.

Supplier directions may say AFTER radio to amp.
From amp OUTPUT to antenna, IOW.
“Where”, is a question to research;
the general purpose answer versus
HA “directed answer” as given here.

I use at both ends. (Mobile. Big truck problems at present).


And I’m new as hell, so . . . .

Employ the Search Function

is a requirement as I see it.

.

 

[ForestRunner98]

While waiting for my Palomar coax filter to arrive I did install a new antenna. A 6’ Skipshooter. Wow..I really like this antenna. Has good TX and RX! So far better than my 4’ Firestik but that could be because it’s longer.



SWR is great! Barely bumps amp off and 1.4 at both ends amp on. I need to get a beefier stud so it doesn’t snap off. Got some good feedback by locals (10 miles) and one had little difficulty hearing me at 35 miles(Disneyland) I figured cause I was parked in the driveway surrounded by houses and garage in front.

 

[Handy Andy]

No THEY were in RFI-Haven with Mickey and Minnie...

 

[ForestRunner98]

No THEY were in RFI-Haven with Mickey and Minnie...

That’s right....it’s still closed!!

 

[Handy Andy]

6' Skipshooter eh?

Nice work - I hope it does you well.

Anything you can do to raise the loading off the rear backside of the SUV and out into the open ABOVE will help in getting the signal out - most certainly!

Good to see you enjoying the hobby.

 

[ForestRunner98]

My coax filter from Palomar Engineers came in!! Threw it on between radio and amp. The results were...not a damn thing changed. No noticeable difference. That noise is still there. So frustrating! I also tried after the amp at the antenna. At all sections of coax where the outer shell makes contact noise shoots up 3 S units.

Now going back to Slomovers post #273 he has one at the radio AND antenna feed. So buy another filter?

 

[Slowmover]

My applications are all mobile.

1). Ferrite toroid at antenna feedpoint.

2). Cube filter (what you have) at radio.

See “Proper Coax Choke Mobile” (thread)

Ferrites on every line/cable. Is how I’m trying it. Both ends. Experiments.

Interference sources is the “real” subject

www.K0BG.com

There’s always some noise. But it’s hard to describe quality and/or quantity.

Sometimes, it’s can I hear thru the noise? Others, is can I hear around it.

Reduction is consisted by me to be success.

But my experience is CB.

Eleven Meter (USB LSB) is still new.

I’m most interested in Installation as I think that prerequisite for all personal advances (licensure, etc.

Installation, offers me a foot in the door. Other pursuits have shown that attention to details matter.

.

 

[Slowmover]

Noise all thru antenna? 100%?

Have you driven to a rural area free of electrical?

Can you park on a dam? A headland?

Tested every single component in the chain? Separately?

These questions I’M NOT asking you to answer.

But to look both FARTHER from current operating conditions (location), and CLOSER at components.

Vehicle Bonding I’ve made into a big deal. Pickup, Peterbilt and aluminum travel trailer all deserve my best.

If I’ve read him correctly, Applegate makes quite a to-do in emphasizing that antenna location will make or break a “quality” Mobile installation.

In other words, it’s first & last. In between is great detail on working with subpar locations.

Think, diagnostic tools.

 

[ForestRunner98]

Thanks for the input Slomover!

I went to www.k0bg.com earlier and also the proper coax mobile choke thread. In fact I had K0bg bookmarked.

The truck is bonded and that helped a ton with SWR.

Yup..noise comes thru at all points.

I am in a very urban area but when doing the “common ground test” level drops 2 S units. So even in a urban setting improvement is potentially there.

I don’t think I can add a ferrite toroid at the antenna feed point. There is no room. I can add some clip-on ferrite beads. I believe Mix 31 are the ones I need. Palomar has those for a pretty good price. Amazon versions don’t tell you the type of mix.

I understand my antenna placement is not ideal but that’s the only option that works for me at this point...hence the 6’ Skipshooter.

The work goes on!

 

[ForestRunner98]

So I am still obsessing on this. Would it be beneficial if I use a toroid but it’s a few inches from the antenna feed?

I can place the toroid between the body and bumper and have the coax re-enter the truck.


Looking from bottom looking up...bottom of pic is the bumper and top of pic is the body.

Reason being is I am not sure how many snap on beads I will need. I read rhat I need more just to match the number of turns on a toroid ring. Yes?

 

[Slowmover]

L

So I am still obsessing on this. Would it be beneficial if I use a toroid but it’s a few inches from the antenna feed?

I can place the toroid between the body and bumper and have the coax re-enter the truck.

View attachment 37087 View attachment 37088
Looking from bottom looking up...bottom of pic is the bumper and top of pic is the body.

Reason being is I am not sure how many snap on beads I will need. I read rhat I need more just to match the number of turns on a toroid ring. Yes?

Look the most recent posts on my 579 Pete Install. Pics of snap-on toroid out in the wind

 

[ForestRunner98]

L


Look the most recent posts on my 579 Pete Install. Pics of snap-on toroid out in the wind

I definitely did! That’s what made me start thinking.

It looks like a 1” snap-on type. 8 turns? That is a much easier way but I am not sure if I will have enough coax. I can always use a barrel connector and add 6’ of JEFA coax I have. With a 240 ring I can wrap it with tighter turns and skip the additional coax.

I know it’s a lot of questions. Thanks!!

 

[Slowmover]

Coax construction drives how tight.

Some RF Chokes sold use a type that can handle that.

K7CRA (I think)

I’ve made (4) different runs of new coax in this project. $$

Yes, 8-turns. 1.0” Palomar 31