Larsen failure after 2yrs

[prcguy]

I've been using the Larsen NMO2/70B 2m/70cm antenna for many years and they have worked well for me. I talked a friend into getting on and the first one he received was defective, infinite VSWR but with no signs of external damage. He got a replacement and its been on his car for about 2yrs. A few months ago he complained of high VSWR even though he could transmit and receive through the antenna.

I checked the antenna on my vehicle and found it resonated at 153MHz on 2m where the match was just fine when the antenna was new. The whip was stock length and already out as far as possible on the coil. I cut the coil open and found some corrosion inside and on the coil wire, which can electrically change the length of the wire. It appears water has entered the top of the coil housing and ran down onto the coil.

Here is a picture inside the coil housing showing the corrosion. This antenna lives in So Cal where we don't get much if any rain.

 

[tweiss3]

I will have to keep this in mind and add a quick sweep to the quarterly checks. I do check that it's tight every month, and have found the top nipple that holds the whip comes partially unscrewed occasionally.

 

[KevinC]

Does it go through car washes?

 

[bharvey2]

Does it go through car washes?

That was my thought too. I usually either wash by hand or, if going through a commercial wash, take the antenna off temporarily and replace it with a cap. That being said, I've never really had a trouble with Larsen antennas I've had. I wonder if they're sticking their label on cheap, imported products now.

 

[wwhitby]

I had heard rumors that Larsen has been having QC problems (specifically, problems with coils) since they moved antenna production to Mexico.

 

[prcguy]

The car does but the owner takes the antenna off. The car lives outside at the curb and no garage but its only rained a few times in the last few years where this antenna spends all of its time.

Does it go through car washes?

 

[mmckenna]

Well, that sucks if their QC is going to hell. They were my go-to for antennas.

Other brands out there, but none that seem to have professional grade stuff that's sold specific for the ham market.

 

[mastr]

I had heard rumors that Larsen has been having QC problems...since they moved antenna production to Mexico.

It would not be the first time that an antenna company had trouble with Mexico based production.

 

[cbehr91]

I have a Larsen NMO150CHW (VHF 1/2 wave) that has gone deaf. NOAA WX signals that are S8-9 on other mobile antennas (including an out-of-band 1/4 wave) are S2 on this Larsen. I checked the antenna rod and there's no signs of corrosion.

 

[ladn]

Most of my Larsen's are 10+ years old and going strong. My newest is about 5 years old (NMO 2/70). It seems to be functioning normally, but I'll take a closer look at it when the weather warms up.

 

[ve3id]

I've been using the Larsen NMO2/70B 2m/70cm antenna for many years and they have worked well for me. I talked a friend into getting on and the first one he received was defective, infinite VSWR but with no signs of external damage. He got a replacement and its been on his car for about 2yrs. A few months ago he complained of high VSWR even though he could transmit and receive through the antenna.

I checked the antenna on my vehicle and found it resonated at 153MHz on 2m where the match was just fine when the antenna was new. The whip was stock length and already out as far as possible on the coil. I cut the coil open and found some corrosion inside and on the coil wire, which can electrically change the length of the wire. It appears water has entered the top of the coil housing and ran down onto the coil.

Here is a picture inside the coil housing showing the corrosion. This antenna lives in So Cal where we don't get much if any rain.

View attachment 127620

Between me and another ham, we now have four NMO2/70 coils that have failed within a couple of years of purchase. Does anybody know if Larsen has made any offers to replace bad coils?