• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

Larsen NMO-27-C testamonials?

Has a slick commercial flair

Needs a happy face? Disney logo?

Unlike the menacing appearance of the tax-dollar-being-used-against-you Larsen?

669BCACD-AB3C-465D-9FCB-0AA704CE06B0.jpeg

Dog dish hubcaps on blackwall versus full covers with whitewalls? Biscayne versus Caprice? I6-250 versus V8-427?

Hell, just mount a Rebel Flag Connex inside.

(Quality of photo and final processing is the giveaway).
.
 
Last edited:
  • Like
Reactions: WECSOG
If a vinyl shrink-tube was applied to a polished chrome or stainless steel antenna, would the antenna still function?
Sure it dont see why not. If your referring to what we call shrink wrap. I had a buddy that was worried about water getting in the joint 1/2 way up a vhf/uhf vertical base antenna. He shrink wrapped the entire thing from the radials to the top... worked fine.
 
  • Like
Reactions: Groundhog KSS-2012
Sure it dont see why not. If your referring to what we call shrink wrap. I had a buddy that was worried about water getting in the joint 1/2 way up a vhf/uhf vertical base antenna. He shrink wrapped the entire thing from the radials to the top... worked fine.
Yes, I am referring to the material used by electricians to cover a spliced wire connection. A heat gun / hair dryer is used to apply the shrink tubing / sleeve. For the folks (like me) who don't like the chrome bases on mobile antennas, the coil / base can be covered with the black shrink tubing.
 
Larsen works fine for barefoot radios - I would never run an amp with one. Rated to 200 watts which means I wouldn't run more than 100 watts through one. I usually go the 50% route to be safe since antenna wattage claims are usually BS.
The instruction / guide sheet with the Larsen was a good "guide" for trimming the antenna for 27Mhz. The antenna was 49" long and the instruction sheet recommended a length of 47" for a roof mount installation without a spring and a length of 46-1/4" with a spring. Being that the antenna is attached to a Third Brake Light Antenna Adapter, I wouldn't consider the antenna to be classified as a "roof mount" installation. Starting with the original 49" long antenna, I trimmed-off 1/2" pieces until the SWR was down to 3 and then I trimmed-off 1/4" pieces until the SWR was below 1.3 on all channels, being 1.3 is on Ch. 40, 1.1 on Ch. 1 and 1.2 on Ch. 20. I'm done! Final length is 46-1/4".
Next task is to compare the transmit and receive of the Larsen and the Browning BR-140-B.
 
I think it was around 49" or so but I had to cut it down quite a bit during tuning. I took a good 3 inches off.

Doesn't look to bad actually and the performance surprised me. I definitely would run any power through it. Rated for 300 watts but I bet anything close to 100 and it will start to get warm.
The length of the Larsen was also 49" and after trimming-off pieces to obtain a 1.1 to 1.3 SWR, the final length is now 46-1/4" and the final length of the Browning BR-140-B is 46-1/8".
 
  • Like
Reactions: Slowmover
Now I know why mine would not tune!!! Guess im gonna have to do some trimming
The "trim chart" which came with the Larsen has a roof-top mounted NMO27B / NMO27C having a trimmed length of 47" without a spring and 46-1/4" with a spring for 27 Mhz. I do not have a spring and the SWR is great at 46-1/4". Go figure! My first cut was 1". I had to remove the black paint / coating to ensure the antenna was fully inserted into the socket before checking the SWR. I don't know if it makes any difference, but I always file the cut-end as flat as possible after I cut the antenna with pliers so as to get that warm and fuzzy feeling that the bottom of the antenna makes good contact with the socket.
 
For CB, I use an Larsen NMO-30 coil, 3 inch spring and I believe. a 60 inch whip trimmed down to around 56 inches or so. Has decent bandwidth. I really like it. I think it's better than any Wilson. But it is limited by power. I dont run POWA, so it works for me. It's sexier, too. I copied it from some dude in Canada that posted his results. I have an NMO-27 CB antenna, but I don't much care for it.

At first, I ran it hard mounted. I use a 4 inch mag mount with it now.
As per Larsen's Trim Chart, the operating range for the NMO30 is 30.0 MHz to 35.0 MHz with antenna lengths from 35-1/4" to 51-9/16". What is the length of your antenna with the NMO30 coil? I am curious if all coils are the same and only the antenna length is different.
 
  • Like
Reactions: Slowmover
The "trim chart" which came with the Larsen has a roof-top mounted NMO27B / NMO27C having a trimmed length of 47" without a spring and 46-1/4" with a spring for 27 Mhz. I do not have a spring and the SWR is great at 46-1/4". Go figure! My first cut was 1". I had to remove the black paint / coating to ensure the antenna was fully inserted into the socket before checking the SWR. I don't know if it makes any difference, but I always file the cut-end as flat as possible after I cut the antenna with pliers so as to get that warm and fuzzy feeling that the bottom of the antenna makes good contact with the socket.


Save the file.

Given the picture posted of, Recon’s Dog, I’d imagine that son-of-a-biscuit could make it shark-bite clean.

.
 

dxChat
Help Users
  • No one is chatting at the moment.