Larsen Triband Antenna Models and Specs

[TexTAC]

I have a Larsen Triband NMO150/450/800 which I really like. I heard there were actually two Larsen Triband models, so I did some online research to find out which one I had. Turns out (1) there are actually 4 Larsen Triband models, (2) two of them are designated with “SF” which I believe stands for “Super Flex”, (3) the information on vendor websites is often inaccurate (even the Larsen website has conflicting data), and (4) there really is not much difference between any of the 4 models in regards to VSWR vs Frequency curves. I spent a lot of time doing this so I thought I would share what I learned…

Data according to Pulse-Larsen website:

PRODUCT NO.​	VHF (MHz)​	UHF (MHz)​	7/8/9 (MHz)​	PEAK GAIN (dBi)​	HEIGHT (in)​
NMO150/450/758	150-174​	430-520​	750-870​	0/5/4​	17.8”​
NMO150/450/758SF	150-174​	430-520​	750-870​	0/5/4​	17.5”​
NMO150/450/800	150-165​	450-470​	806-940​	0/5/4​	16.5”​
NMO150/450/800SF	150-165​	450-470​	806-960​	0/5/4​	17.7”​

Data according to online vendors:

• NMO150/450/758 – The Antenna Farm lists the VHF range as 150-165 (instead of 150-174), UHF range as 450-470 (instead of 430-520), gain us “unity” (instead of 0/5/4), and the height as 16.5” (instead of 17.8”).
• NMO150/450/758SF – Arcadian lists the height at 16.5’ (instead of 17.5”).
• NMO150/450/800 – The Antenna Farm lists gain as “unity” (instead of 0/5/4) . The Ham Radio Outlets lists the 7/8/9 range as 806-960 (instead of 806-940) and the height at “approximately 20 inches” (instead of 16.5”). Tessco lists the 7/8/9 range as 806-960 (instead of 806-940) and the gain as 2dBi (instead of 0/5/4).
• NMO150/450/800SF – Both Tessco and Arcadian list the VHF range as 150-174 (instead of 150-165), UHF range as 430-520 (instead of 450-470), and gain at 0/5/5 (instead of 0/5/4). However, they also have a Technical Data Sheet which looks like it came directly from Pulse-Larsen which agrees with the data on the Tessco and Arcadian websites but disagrees with the data on the Pulse-Larsen website.

VSWR Vs Frequency Curves:

I was able to find VSWR Vs Frequency curves for all but the NMO150/450/800 model on the Tessco and Arcadian websites. These are data sheets provided directly from Pulse Larsen. Ironically, the VSWR Vs Frequency curves for the NMO150/450/758 (dated June 11, 2018) and the NMO150/450/800SF (dated September 4, 2020) models appear to be exactly the same. The VSWR Vs Frequency curve for the NMO150/450/758SF (dated January 23, 2020) is slightly different but not by much. All three models appear to have useable frequencies between 150-174, 430-520, and 750-960 MHz according to the graphs regardless of what is listed in the specifications.

 

[mmckenna]

I've got a few of those on order. Tessco had them backordered for about a month, but they shipped last week and are sitting in our receiving. As soon as they get in my hands, I was planning on installing them on my truck roof and running them through my spectrum analyzer/tracking generator to see how they look.

 

[TexTAC]

I'd be interested in seeing the results when you are through.

 

[mmckenna]

That was my plan when I ordered them.

I have one NMO 150-174/430-520/750-870 on order
and
one NMO 150-174/430-520/806-960 on order.

I may try some others in the near future. I'll be migrating our PD to multiband radios and wanted to get a cross section of the available antennas so we can try them out. I don't want to rely on the high price options the manufacturer provides.

 

[CanesFan95]

Always wondered, are these OK for transmit, or receive only?

 

[TexTAC]

I only use them for scanning/receiving, but they each have a 100 Watt power rating so I assume that is for transmitting?

 

[mmckenna]

Always wondered, are these OK for transmit, or receive only?

When Larsen first came out with the tri-band model many years ago, it was marketed as a scanner antenna. Some time later they started selling them as multiband antennas.

They are good for transmit. In fact the newer ones are designed around the capabilities of the more modern multiband mobile radios. The ones I purchased are going to be trialed with Harris XL-200M's.

 

[devicelab]

I'd be interested in seeing the results when you are through.

You obviously didn't see my posts on these exact antennas including VNA sweeps.

Larsen TRI-Band VNA Sweep (Part Deux) + Laird Scanner and COMPACtenna SCAN III

Okay I have more egg on my face. I forgot about my scanner NMO cabling in the SUV and grabbed the wrong coax. THIS time I have labelled my connectors so I know which is which! Here are the real VNA sweeps between the older Larsen TRI-BAND and the new Larsen 150/450/758 (which coincidentally...

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