2m/70cm mobile antenna issue.

[CptJbud]

Purchased a Diamond MR77 to use mobile with HT, with HT battery power. Reviews have been great on this antenna. Mounted center of roof (Hyundai Kona). When vehicle is running, I get great reception - with or without gps/infotainment car goodies on.. When in motion, however, it sounds like the signal is clipping. There is extra noise along with what almost seems like some of the signal is squelching out rapidly.. Is this "picket fencing"? Anything I can do about it? Would some ferrite beads help on the coax? Was also thinking of grounding the radio case through counter poise to cig lighter ground..
Appreciate any suggestions

 

[mrweather]

The MR77 appears to be a 1/4 wave antenna which will be more prone to picket fencing. No ferrites or grounding will help with that.

What other noises are you hearing?

 

[CptJbud]

I believe it's 1/4 on 2 meter and 1/2 on 70cm. Happens on both bands equally though.. No other noises. Actually very clean with decent distance (ems and sheriff repeaters 40+ miles away) - just dirty and clippy while in motion..

 

[mmckenna]

Yeah, picket fencing or something is loose. Make sure the whip is tightened down all the way the the coax is good.

 

[AK9R]

I believe it's 1/4 on 2 meter and 1/2 on 70cm.

Diamond says it's a 5/8 wave on 70cm.

 

[bill4long]

Get a Diamond 770 variant. You'll love it. Folds over, and is 1 x 1/2 for 2m and 2 x 5/8 for 70cm.

 

[KC3ECJ]

What terrain are you in? If you have mountains, stay with the 1/4 wave at 2 meters.

 

[bill4long]

What terrain are you in? If you have mountains, stay with the 1/4 wave at 2 meters.

Huh? Where are you getting that?

 

[CptJbud]

What terrain are you in? If you have mountains, stay with the 1/4 wave at 2 meters.

North Florida just trees

 

[jwt873]

I'm thinking perhaps something is loose as well.

I believe the whip for your antenna is painted black.. I'd make sure the set screw is making good contact with the whip. The set screw might not have penetrated the paint when it was tightened down, in which case the resistance combined with the waving of the antenna in the wind might be causing the problems. If the whip is painted (or anodized) black make sure the part that makes contact with the set screw is clean.

 

[KC3ECJ]

Huh? Where are you getting that?

Radiation pattern.

 

[nd5y]

What kind of radio is it?
Some Chinese radios with the transceiver-on-a-chip design have poorly designed firmware settings that cause excessive picket fencing or geiger counter sounding noises when moving that doesn't occur in real radios.

 

[CptJbud]

What kind of radio is it?
Some Chinese radios with the transceiver-on-a-chip design have poorly designed firmware settings that cause excessive picket fencing or geiger counter sounding noises when moving that doesn't occur in real radios.

Geiger counter noises - that's what I'm hearing in the backgtound.. Baofeng 8hp

 

[nd5y]

Baofeng 8hp

Then that's what your problem is. Search the forum for "baofeng geiger counter" there are some other threads where somebody explained what causes it.
It's not loose connections.
It's not normal picket fencing from moving.
It's Baofengs poor receiver design.

 

[chief21]

Generally, Baofeng radios don't do well when connected to a base or mobile antenna. This is likely due to the single-chip receiver design and the lack of any real filtering.

 

[CptJbud]

Thanks everyone!

 

[scanmanmi]

Search the forum for "baofeng geiger counter"

I've searched the Forum and Google and nothing comes up.

 

[bill4long]

Thanks everyone!

You bet. This is all about helping brother hams and spreading the love around.

 

[KevinC]

I've searched the Forum and Google and nothing comes up.

Here's one, took a out 15 seconds to find it.

Baofeng receiving problems while driving

FM radios are usually immune to pulse type ignition noise from spark plugs, etc due to some very high gain limiter amplifiers that run into saturation and do not respond to amplitude modulated signals like spark plugs. A good FM transceiver will be into hard limiting within 10 or 15dB of its...

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