NMO34 with the W640 (64" whip) vs NMO-27 vs CWB-27

[K9KLC]

I have a laird cb27 & laird hood lip mount, I’ll be installing them on 2015 infinity qx60. This will be a compromise install, it will be our family’s main city & parking garage vehicle.

Curious to see what you end up with on this.

 

[RFI-EMI-GUY]

Great job by PRC-Guy and K6GBW !

 

[prcguy]

We have seen the Laird CW27 slightly outperform the Larsen NMO27 and have discussed the Chinese connection to Larsen and some reported failures with late model Larsen antennas. When is someone going to come up with a President Colorado 800WB antenna to test? Its supposed to cover 21 to 30MHz without tuning and its got a 54" whip. It could be the new replacement for the out of production Laird CW27 but we won't know until someone blows $120 on the Colorado. Anyone?

 

[RFI-EMI-GUY]

We have seen the Laird CW27 slightly outperform the Larsen NMO27 and have discussed the Chinese connection to Larsen and some reported failures with late model Larsen antennas. When is someone going to come up with a President Colorado 800WB antenna to test? Its supposed to cover 21 to 30MHz without tuning and its got a 54" whip. It could be the new replacement for the out of production Laird CW27 but we won't know until someone blows $120 on the Colorado. Anyone?

The two things that hold me back.
1) The "Fiber/Graphite whip. Is that a substrate for a copper wire or is it a long resistor?
2) The SO239 connector. Can I "NMO" it without a hassle?

 

[prcguy]

View attachment 193206

The two things that hold me back.
1) The "Fiber/Graphite whip. Is that a substrate for a copper wire or is it a long resistor?
2) The SO239 connector. Can I "NMO" it without a hassle?

I've never seen a graphite or resistive whip and that could broaden the BW at the expense of loss. It would also heat up depending on the loss and I would be surprised if the whip does not have a low resistance conductive wire inside. There are low profile NMO to SO239 adapters that should work fine.

So, are ya gonna buy one for me to test?

 

[slowmover]

NMO to SO-239 Antenna Adapter - ARS-4930

 

[prcguy]

NMO to SO-239 Antenna Adapter - ARS-4930

I have one that is much lower profile than that. You want the base of the antenna to be as close as possible to the ground plane like the antenna was mounted on an NMO. Raising it up can change impedance and increase losses.

 

[prcguy]

I found my low profile version and here it is next to a Tram version. Not sure who made it.

 

[slowmover]

I found my low profile version and here it is next to a Tram version. Not sure who made it.

View attachment 193208

In several searches over several years I haven’t seen one that low. Or of “quality”, so far as I can tell.

I bought an OPEK just to have something.

.

 

[prcguy]

I found two similar but different low profile adapters on fleabay. One is a no name and the other is a Larsen. Mine has slight differences to both and I don't remember where I got it.

NMO to SO-239 UHF Female Adapter, Brass, Antenna Mount, Chrome Plated, Ham | eBay

Converts standard NMO antenna mount to a UHF Female (SO-239). This adapter allows any NMO mount to accept a Male UHF (PL-259) Type antenna. Consists of a screw-on NMO base with a female UHF connector on top.

www.ebay.com

NMO to SO-239 (UHF Female) Adapter - Larsen NMOTEST1 | eBay

MPN: NMOTEST1. Larsen NMOTEST1. NMO to SO-239 (UHF Female) Adapter. NMO to UHF Female (SO-239) Adapter. Radiall Larsen. Police, Fire, EMS, Gov & Amateur. Expert Support. RF Electronics Experience.

www.ebay.com

 

[slowmover]

NMO MOUNT UHF FEMALE
(SO239) TEST ADAPTER

LARSEN NMOTEST1

UPC 729198263867

At: MOUSER

https://mou.sr/4ipT245

This high-quality adapter is designed to check your antenna feedline and radio simultaneously, ensuring optimal functionality and performance.



.

 

[RFI-EMI-GUY]

I've never seen a graphite or resistive whip and that could broaden the BW at the expense of loss. It would also heat up depending on the loss and I would be surprised if the whip does not have a low resistance conductive wire inside. There are low profile NMO to SO239 adapters that should work fine.

So, are ya gonna buy one for me to test?

Hmmm. Thinking on that...

 

[RFI-EMI-GUY]

Hmmm. Thinking on that...

Can those be purchased domestically?

 

[prcguy]

Can those be purchased domestically?

Walcott radio in Indiana is one, there might be more.

 

[slowmover]

PRESIDENT Colorado 800
21-30 MHz, 54” NMO Antenna

President Electronics Colorado 800 WB 21-30 MHz HF Antenna with UHF Connector

Check out this President COLORADO 800 at www.WalcottRadio.com

www.walcottradio.com

Code: CYBER25

$119.95 today


“The Colorado 800 WB is a wide band mobile antenna specifically designed to give maximum performance in the CB, 10 meter, and 12 meter bands.

These antennas are very broad-banded but still have an SWR ≤ 2. The fiber/graphite whip is not meant to be cut or trimmed. Higher than normal SWR may indicate problems with coax, ground plane, or installation.

Rated at 140 watts PeP and measures in at only 4.5 feet. Requires a UHF SO-239 style antenna mount (not included).”



.

 

[slowmover]

Walcott radio in Indiana is one, there might be more.

Walcott Radio is across IH80 from IOWA 80, the world’s largest truckstop in Walcott, IA.

Great retail selection on hand.
Website doesn’t adequately convey this.

You ain’t lived until . . . .

 

[RFI-EMI-GUY]

I've never seen a graphite or resistive whip and that could broaden the BW at the expense of loss. It would also heat up depending on the loss and I would be surprised if the whip does not have a low resistance conductive wire inside. There are low profile NMO to SO239 adapters that should work fine.

So, are ya gonna buy one for me to test?

I sent you a message.

 

[slowmover]

We have seen the Laird CW27 slightly outperform the Larsen NMO27 and have discussed the Chinese connection to Larsen and some reported failures with late model Larsen antennas. When is someone going to come up with a President Colorado 800WB antenna to test? Its supposed to cover 21 to 30MHz without tuning and its got a 54" whip. It could be the new replacement for the out of production Laird CW27 but we won't know until someone blows $120 on the Colorado. Anyone?

The Man Behind the Counter
Forty-seven years, you say?



I had the watchband and a similar tie-tac.
Wish I could still grow the hair.

.

 

[prcguy]

The Man Behind the Counter
Forty-seven years, you say?

View attachment 193423

I had the watchband and a similar tie-tac.
Wish I could still grow the hair.

.

I was that guy 48yrs ago. Did counter sales, CB, car stereo, commercial radio, installs and repairs. Also opened and stocked a satellite store 50mi away and drove there and managed it every day for 6mo. Sunshine Radio, Colorado Springs and Pueblo, CO from about 1976 to 1981.

Never wore a tie, don't think I owned one back then.

 

[RFI-EMI-GUY]

My second CB radio Comstat 25A (Obtained as gift 1968 with Turner Plus 2 desk mike)

My first CB radio HB-555 (Bought in 1965 with insurance money from bike stolen)



My third CB radio TRC-465 (Should have kept this one, bought for road trip 1994)