Adjustments for resonance

[Nick hatz]

So got the mount and the new 102” whip. Old one corroded on threads. Please see pics on antenna analyzer. Not sure what to do. Any help would be great.
resonance frequency is higher than the 11 meter band so the antenna is to long? I’ve read k0bg several times. I understand x=0 but how to get it there. Is antenna to long or to short?

 

[BJ radionut]

Nick: Antenna is too SHORT...put your quick change adaptor on sweeping it again, bet it will fall in close enough for your usage! (needs 2-3 + inches)

To lower the resonance frequency...antenna needs to be longer.
Your pretty damn close!
All the Best
Gary

 

[Marconi]

BJ like you say, it really looks like Nick's antenna is short, but he explains this away to Secret Squirrel in Nick's threads "High SWR" or "Antenna Tuning" in the "General CB Service Discussion."

Nick tells Squirrel he is using a 6" mount.

Even if Nick was just using a 102" whip alone, just about any where on the truck, I doubt the match would be off as much a he shows on his RE 55 analyzer @ 28.672 MHz.

I could be wrong, but among other likely issues, I don't think Nick has a good ground, and that is why his 102" install looks so short.

Slowmover once referred me to Nicks thread (another story) and I found SM's post below.

Antenna tuning

I think SM politely hit the nail on the head in his comment to Nick and he even underlined the important words.

 

[Nick hatz]

I’ve read the book front to cover multiple times SWR not an issue. Trying to tune the antenna for resonance. The book does not mention much shows how to use analyzer but not how to make adjustments.
Mount to bumper, mount to bed, mount to exhaust, mount to cab, mount to hood all checked all readings are .001 ohms or there about.
Mount to antenna OL.
I did everything I knew how before posting.

 

[Nick hatz]

This is it. Doesn’t explain any of the values or anything. Power of the Internet I’ve been doing and digging and looking. Ordered the AARL.

 

[Slowmover]

I’ve read the book front to cover multiple times SWR not an issue. Trying to tune the antenna for resonance. The book does not mention much shows how to use analyzer but not how to make adjustments.
Mount to bumper, mount to bed, mount to exhaust, mount to cab, mount to hood all checked all readings are .001 ohms or there about.
Mount to antenna OL.
I did everything I knew how before posting.

I’ve enjoyed your threads on this install as if you’ve pulled out in traffic and have passed me, but are still in sight up ahead.

Might be this Peterbilt will out-pull you on the next grade. (My CTD Dodge still sits, but, soon . . . !)

So . . with kindness, if my experience as a new guy is of any help, it’s still there in front of you.

Affix wide flat bandage across forehead now. The slap of your palm won’t sting as much. (Gives me a headache every time).

No one’s trying to be mysterioso.

.

 

[Road Squawker]

.... Not sure what to do. ... Is antenna to long or to short?

EZ way to remember,... if the antenna is better @ LOWER freqs, then it is too LONG

Lower is Long

 

[Nick hatz]

I totally understand. If these post help one person it’s successful. Between bonding the truck and doing as much research as possible. K0bg is awesome. For some reason after I read it still hard to understand. I’m more of a hands-on person. I will get this thing I’m not going to let it beat me I have learned so much. It’s easy to pay somebody but then you’re left with no knowledge
Everything I bought was top-of-the-line so that when it’s done I won’t have to deal with it later on in life. Everybody has been such a great help

 

[Marconi]

Nick, I appreciate your ZEAL, but antenna understanding does not always come easy and the analyzer makes understand more complicated, because it is giving you the nitty-gritty details for your matching setup and that gets very technical.

The manual probably gives a general description of the analyzer, its settings, and general operations. There may also be some particular project type comments in the back of the manual that go into some limited step scenarios that might be helpful in using your 55.

How do you have the 55 attached to your antenna?

Do you have a close up picture of your antenna mount that you told Squirrel was 6" tall?

 

[fourstringburn]

A 102 whip isn't 50 ohms, it's around 33 ohms so your analyzer is correct for 11 meters.

Read K0BG's chapter about antenna matching using inductive matching and shunt coils to bring up the antenna feedpoint impedance to 50 ohms on any given frequency within the range of your antenna.

Is this necessary?

If you're a perfectionist or like to experiment and learn, than yes!

 

[Nick hatz]

Analyzer is hooked up in the cab of the truck where it plugs into the radio. I did try a shorter piece of coax at the antenna. Same results. It’s the same mount I started with I just replaced it with the one that does not have a short in it. The mount measures 3 inches from the top of the plate where the antenna screws in and it was 3 inches below the mount. So from coax to antenna mount is exactly 6 inches. The Geotool mount didn’t fit. Really nice smell I wish I could’ve used it

 

[Nick hatz]

Geotool mount.

 

[groundwire]

Standing waves are due to an impedance mismatch between the antenna and transmission line. Antenna resonance and correct impedance will never occur in the same place. Its either resonant with mismatch impedance or matched impedance and non resonant. The correct way to tune an antenna is adjust it for resonance on the desired frequency and then match impedance using some kind of matching network. Ie: capacitance or inductance. All other info is cb myth

 

[Slowmover]

“. . . . All other info is cb myth

Not myth. LEGEND!

In CB land we know (Jimmy Stewart & John Wayne) that, “when truth and legend collide, repeat the legend!”

(Post well-said).

.

 

[Nick hatz]

I got the whip adjuster and installed it today tuned the antenna to resonance on my frequency I use most.
x=0
Swr 1:1.5
Phase 180 deg
Ohms 34 I know that’s a little low.
This thing screams now.
I really appreciate everyone’s help it’s been a great learning experience. It was worth every ounce of sweat in this Texas heat getting this set up put together.