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

[K9KLC]

The MFJ 939 with an A99 gets amazingly wide coverage. In fact, the longest contact I’ve ever made was on that set up. I reached Indonesia on 10m with only 100 watts. At week later I got Israel, Hungary and Ireland one right after the other.

Have you used that for any bands other than 10, 11, or 12 meters?

 

[K6GBW]

Have you used that for any bands other than 10, 11, or 12 meters?

I got it to tune up all the way down to 20 meters. On 20 meters it was a dog, but it did work, on 17 meters it wasn't bad and on 15, 12, 11 and 10 meters it was actually really good.

 

[K9KLC]

I got it to tune up all the way down to 20 meters. On 20 meters it was a dog, but it did work, on 17 meters it wasn't bad and on 15, 12, 11 and 10 meters it was actually really good.

Thanks.

 

[RFI-EMI-GUY]

Interesting idea. But if you knew just how much radio and antenna sh*t is laying around here clogging my yard and garage you would know my wifee would take the same saw I used to cut out the SUV roof and she would use it on me. Then she would look up my browsing history, find this thread and you would be next on her list with the bloody saw for suggesting the idea.

Someone, maybe Brian, will show up here hopefully with an NMO27 and a roof mounted NMO and we will go to work testing, then they will go home not leaving any cut off SUV roof, thank you very much.

You could make a Pergola from it , hang some fern plants and throw some old lawn chairs under it and she would not know the difference. you've watched the Red Green show haven't you? Meanwhile I am going to buy a "vacuum cleaner belt" from a shady guy in New Mexico for $250G. bye!

 

[billdean]

Still cutting down the NMO30 whip. The dip on the NanoVNA is about channel 40 now. I still have acceptable SWR on channel 19 but if I go anymore I will probably have unacceptable SWR soon. I am able to use the 10 meter band but how well I don’t know. I have the radio set to cancel the mic out at SWR 3.0 to 1. The SWR on 28.300 to 28.500 is about 2.25 to 1. Here are NanoVNA graphs.

 

[prcguy]

You could make a Pergola from it , hang some fern plants and throw some old lawn chairs under it and she would not know the difference. you've watched the Red Green show haven't you? Meanwhile I am going to buy a "vacuum cleaner belt" from a shady guy in New Mexico for $250G. bye!

My wife is looking your house up on Google earth. Be afraid.

 

[RFI-EMI-GUY]

My wife is looking your house up on Google earth. Be afraid.

I had best be going....

 

[billdean]

After thinking about the NMO30 and the 65" whip I believe it is not a very good system to use as a one antenna system for both 10 and 11 meters. Operating the radio at the extreme end of the 11 meter band to get a questionable SWR in the 10 meter range seems like it maybe hard on the radio itself. It seems that the MNO27 would be a better antenna to use for something like this. Better yet would be a 2 antenna system tuned to the respected bands with a coax switch to switch from one antenna to another. Of coarse your situation maybe different with a different vehicle but for the F-350 it doesn't seem to work well.

 

[K6GBW]

These base loaded antennas were never meant to be that wide banded. An antenna switch and, depending on power, a tuner is probably the best answer. PRCGuy and I are meeting tomorrow morning to test two antennas ( NMO27 and CW27). At least I think that’s the two. So we’ll see what that shows.

 

[K9KLC]

After thinking about the NMO30 and the 65" whip I believe it is not a very good system to use as a one antenna system for both 10 and 11 meters. Operating the radio at the extreme end of the 11 meter band to get a questionable SWR in the 10 meter range seems like it maybe hard on the radio itself. It seems that the MNO27 would be a better antenna to use for something like this. Better yet would be a 2 antenna system tuned to the respected bands with a coax switch to switch from one antenna to another. Of coarse your situation maybe different with a different vehicle but for the F-350 it doesn't seem to work well.

I'm leaning more and more towards two antennas and honestly two radios. One for CB and one for "ham" usage. This will negate the possibilities of an NMO mount for all antennas but at some point it's more about talking than looks.

If I had your truck and no ladder racks I know what I would do but on the work truck and my 2016 ford PIU I need to do things a little differently. Thanks for all your testing. I appreciate you took the time to do it and post the plots on the VNA

 

[K9KLC]

These base loaded antennas were never meant to be that wide banded. An antenna switch and, depending on power, a tuner is probably the best answer. PRCGuy and I are meeting tomorrow morning to test two antennas ( NMO27 and CW27). At least I think that’s the two. So we’ll see what that shows.

I'm anxious to see the of this but given the CWB is unobtainable for the most part, most of us will just have to fantasize about getting one, one day maybe a yard sale or eBay. Please keep us posted.

 

[kk9h]

I have an NMO30 on a NMO-MM magnet mount that I use with an Anytone AT-6666 Pro on road trips. I cut two whips for it, one for 11 meters (27.200 center) and one for 10 meters (28.400 center). The 11M whip is 61 1/4” long and the 10M whip is 56 1/4” long. It is quite simple to unscrew these whips to exchange them. This antenna system works beautifully for me on both bands, highly recommended.

 

[WSAC829]

I'm leaning more and more towards two antennas and honestly two radios. One for CB and one for "ham" usage.

Maybe look in to a Xiegu G90. One simple mod opens up TX for 11 meter and more. It also has a stellar built in ATU that can tune anything, including a rocket stove. This would make for an excellent 1 radio, 1 antenna setup.

 

[prcguy]

Maybe look in to a Xiegu G90. One simple mod opens up TX for 11 meter and more. It also has a stellar built in ATU that can tune anything, including a rocket stove. This would make for an excellent 1 radio, 1 antenna setup.

Its a 20W radio compared to some mentioned here that are 40 to 60W. Plus its AM modulation completely sucks compare to an Anytone, President or any other purposely made CB radio.

 

[K9KLC]

Maybe look in to a Xiegu G90. One simple mod opens up TX for 11 meter and more. It also has a stellar built in ATU that can tune anything, including a rocket stove. This would make for an excellent 1 radio, 1 antenna setup.

Thanks, I've looked at several of those types (cause like you know I need another HF radio ) just to have something else to play with and you know, give my wife something else to discuss with me. I would honestly probably just run one of the CB "type" things I have laying around here doing nothing however and then do something else for HF ham, most likely 40-10 meters if it comes down to it. I've got enough here though honestly to not have to buy a new(er) radio. That being said, if an Icom 7100 presented itself at the right price, it would be on the way here. A few "minor" adjustments, the correct microphone and modification, and you can get at least acceptable AM modulation on the thing. Honestly I'm told the way I have my Yaesu FT-450D set up it's not too bad on AM (or so I'm told). after some slight adjustments to it and the microphone.

 

[K9KLC]

Plus its AM modulation completely sucks compare to an Anytone, President or any other purposely made CB radio.

Never run one so I cannot comment. Frankly a lot of "out of the box" CB's made modulation sucks on AM. It always has especially if you're talking about "actual CB's marketed as CB's. I cannot comment to the new crop of Exports which yes are frankly made to use on the CB band, I've not checked one lately. I did check a 5555 a while back and it seemed pretty good for something right out of a box, but then we made it better. This was likely the first version when that radio first came out. I don't know if newer versions are any different.

 

[K9KLC]

I have an NMO30 on a NMO-MM magnet mount that I use with an Anytone AT-6666 Pro on road trips. I cut two whips for it, one for 11 meters (27.200 center) and one for 10 meters (28.400 center). The 11M whip is 61 1/4” long and the 10M whip is 56 1/4” long. It is quite simple to unscrew these whips to exchange them. This antenna system works beautifully for me on both bands, highly recommended.

This is likely the quickest and easiest answer if you have a 10-11 meter radio. Thanks for the report.

 

[WSAC829]

Its a 20W radio compared to some mentioned here that are 40 to 60W. Plus its AM modulation completely sucks

Me and thousands of others say otherwise. I’ve talked all over the world on that thing with 20 watts or less, and its AM modulation, while not “Super Bowl” punchy is more than adequate. It’s better than a lot of the big name HF rigs on AM.

 

[prcguy]

Me and thousands of others say otherwise. I’ve talked all over the world on that thing with 20 watts or less, and its AM modulation, while not “Super Bowl” punchy is more than adequate. It’s better than a lot of the big name HF rigs on AM.

A $20 CB with stock mic has much better AM modulation than any current HF amateur rig I've seen and I've seem most of them. Most HF amateur rigs run USB with a carrier for AM and it can never sound good. Newer HF rigs use DSP or computer simulation of an AM signal on transmit and even that's not very good.

Try a peak reading wattmeter on a modern HF amateur rig. With the radio set for about 20-25W carrier it should show 80-100W at full modulation, but they don't. I've got an Icom 7300, 7610 and Elecraft K3 in front of me right now and it doesn't matter what mic or mic preamp or rack full of audio gear I use, AM transmit audio is blaaa because AM is an afterthought.

 

[RFI-EMI-GUY]

I wonder if increasing the whip diameter on an NMO-27 or NMO-30 would gain much bandwidth? I have seen automobile AM/FM whips with a spiral running up them that I believe is for reducing the wind drag.

Could a standard whip have a spiral wire of stainless or brass, tack welded most of the length and would that be sufficient to increase bandwidth?