Yaesu/Kenwood Radios, Antenna/Antenna Location Comparison

[Hillbilly Heaven]

Why? If you are using dual band radios limit yourself to the Hustler? Since you tested the Diamond 770 vs the Hustler why not go with the 7900 instead? You give up very little "Claimed" gain 5 vs 5.2 plus you have UHF and it is 22 inches shorter.

 

[vtsoundman]

Why? If you are using dual band radios limit yourself to the Hustler? Since you tested the Diamond 770 vs the Hustler why not go with the 7900 instead? You give up very little "Claimed" gain 5 vs 5.2 plus you have UHF and it is 22 inches shorter.

The Hustlers are a very inexpensive rugged antenna with a very solid reputation...and if this didn't work, a counterpoise kit is cheap so I could convert it for base station useage at the house...there are also several have used the 144 for HF use - which seemed interesting.

You're talking about the super gainers? I couldn't see spending the money on a 7900 when several folks have told me it won't standup to trail use.

I was also interested in what is possible with an easy to deploy antenna in an attempt to maximize an omni 2M setup. The setup had a duplexer with a 70cm/440 antenna during xband ops; I am experimenting with a setup that would be easy for a user (not enthusiast) to deploy for serval days on a vehicle (my wife and I often remote camp/hike in the mountains). Sometimes we will park one vehicle at one end and hike to it from another...The Hustler's performance was quite impressive...

 

[vtsoundman]

@DaveInDenver Awesome post...thx. I'm still digesting it...

What do you think of 0.64 wavelength antennas? There are no vertical/omni's available that I know of that are tuned for that wavelength at 2M (or any other band). I read an article about them a year or so ago...the benefits seemed intriguing....and I like the way the pattern looks based your plots.

 

[DaveInDenver]

I run a 5/8th wavelength Larsen NMO150 for my APRS antenna. Is that what you mean by 0.64? It'll have a little bit of gain and doesn't seem as sensitive to a good ground as a 1/4.

 

[DaveInDenver]

Proportional and Smart Beaconing rarely works as advertised/described in my experience. It works fine for crusing around town, but becomes wildly inconsistent if you're using it on trails.

Have been thinking about what you said about Smart Beacon. I mentioned I run an Argent Tracker3 with setting low speed = 5 MPH transmit at 300 sec intervals, fast speed = 55 MPG transmit at 75 sec intervals, turn of 28 degrees and never more than 60 seconds. I also have it set to skip one beacon when it hears itself. I think the implementation has a lot to do with how effective it is. The radio in my case is 5 watts and the antenna is currently an NMO150 mounted on my windshield cowling.

This is a typical resultant track at Interstate speeds.



This is an example at 4WD low speeds.

 

[DaveInDenver]

FWIW, I do have the advantage of terrain for hitting major digipeaters and iGates.

 

[vtsoundman]

One thing I will have to test next time out is a 5/8 2m antenna to see the difference between the 1/2 wave and 5/8. The 5/8 would have to be mag mount in the center of the hood for a proper ground plane, but it would be a comparison nonetheless. The Husles co-linear 5/8 over 1/4 was the clear winner,but at 7' or so, is a bit unweidly.

I'm in the process of looking at some beam style antennas (yagi etc) and evalating them for portability...

For those that say ham is a waste of money for EM Comms, I used to be one of those people...no more. Had two issues and the ham radio saved my bacon twice.

(1) Once in the sprinter, I blew a hose and belched PS fluid all over the place. A fellow ham heard my call and saved the day...he drove an hour off the mtn down to a gas station to get some PS fluid and then ran it back up.

(2) Dog got a stick impaled (or so I thought) in his paw. Was able to communicate with my wife in the SF Bay area (175 miles away) via repeater!! ...she told me which way to go to get to a vet ER...NO cell service. It would have been an 1.5hr difference if I went the wrong direction. Dog turned out to be OK - the stick was jammed/cemented with sap, but his paw was covered in blood.

@DaveInDenver I will have to grab some tracks off aprs.fi and post it....yours look pretty good.

RE: 5/8 vs 0.64 - I might be wrong about the 0.64 number (can't find the article), but it mentions there being little to no commercial availability of this fractional wavelength...I'll see if I can't dig it up.

 

[DaveInDenver]

Oh, gotcha. Never heard of such a beast so I assumed 0.64 was roughly rounded 5/8. I can't imagine the difference would be tremendous since a 5/8th wavelength antenna will be ~0.64 at the upper frequency of it's bandwidth. For example Larsen quotes 6% as the NMO150 2.0 VSWR bandwidth.

So if you cut it for 145 MHz that yields a 2.0675 m wavelength. So 5/8th of that 1.292 m or 50.874 inches. That 6% bandwidth indicates it's got 8.7 MHz of spectrum under 2.0 VSWR. So the upper limit at 145 + 8.7/2 = 149.35 MHz. Which is 2.001 m wavelength and that 1.292 m antenna is actually 0.646 wavelengths long.

Unless you're saying making the antenna resonant at 0.64 wavelength with the matching network. I can't claim to ever have heard anything about it. You'd have to run NEC simulations to see if what it does and if it's worth trying to transform the impedance.

 

[vtsoundman]

Few Updates to the thread. Wow - wish I could edit that post - horrid grammar and spelling. Phones are no bueno for long messages. Glad folks were able to benefit from it. The Kenwoods remain the better radios for all things xmit/rcv. The Yaesu's used to be easier to deal with for entering data on the fly....but I have gotten better with the Kenwoods.

The Yaesu FTM-70D handheld continues to disappoint in a big way. That radio makes me mad. battery life is poor...the add'l C4FM functionality would be the ONLY reason to buy it.

I have yet to break/bend the Diamond 770 antenna despite bending the crap out of it. I did manage to break a fiberglass CB antenna on the same branches (that was mounted to the rear license plate mount). I did manage to tweak the mount slightly when a branch hit the base, but straightened it.

I tested a 5/8 Diamond and 1/4 wave Chinese clone antenna on the fender mount. Dismal performance when compared to a decent 1/2 wave on 2m and 70cm. Unless your contact is close, forget it. Stick with a dual band 2m 1/2 wave antenna.

With the 5/8 and 1/4 wave antennas center mag mount on the hood - great unidirectional performance. There was much much less dependence on various door positions (open/closed) then when compared to the 2M mounted on the RT fender mount _for fringe contacts_. Folks will tell you that ground plans do not impact 1/2 antenna performance - but that has proven to be false with fringe transmissions. When center mounted on hood mag mount, the 5/8 antenna has better quieting into fringe assuming the repeaters, but not enough for me to be mobile with it.

sent via cone of silence