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paulmbowers

Latest Comms Update But wait... there's more!

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6 minutes ago, PbdBlue said:

Interesting. Do you know which colored wires are wired to which pins?

No. I have these pictures, and you're more than welcome to come by and have a look yourself. The only way I could do it myself is if I had access to..say...an electron microscope.

 

And micro soldering skills.

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16 minutes ago, PbdBlue said:

In order to use an  antenna without a ground plane it must be a half wave antenna. A half wave antenna without a ground plane will perform essentially as a quarter wave with the other quarter wave segment acting as a ground plane. Not very efficient but much better than a rubber duck. Any quarter wave antenna must have a ground plane to perform correctly and you will not be able to tune a quarter wave antenna to an acceptable SWR without a ground plane. Not good for performance and not particularly good for the transmit section of your radio. Half wave antennas are typically ~38" long however Comet makes a shortened version using a loading coil that's 27". Still kind of long but a little better.

https://www.amazon.com/Comet-SS-680SB-Spring-Antenna-Warranty/dp/B00Q5I8OK4/ref=sr_1_1?ie=UTF8&qid=1517174214&sr=8-1&keywords=ss-680sb

Yes.

 

But.

 

There are ways to create ground planes- for example, should I mount the 1/4 wave antenna to a rear fender, I could line the underside of the fender with foil (from my hat) or metal screening. It'd be small, and the spec is something like 24" in each direction...but maybe.

The way to test all this is with an SWR bridge and some pretty sophisticated test equipment- to which I have secondary access. :  )

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41 minutes ago, paulmbowers said:

No. I have these pictures, and you're more than welcome to come by and have a look yourself. The only way I could do it myself is if I had access to..say...an electron microscope.

 

And micro soldering skills.

I may do that. Not a difficult mod to make. I'll let you know.

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37 minutes ago, paulmbowers said:

Yes.

 

But.

 

There are ways to create ground planes- for example, should I mount the 1/4 wave antenna to a rear fender, I could line the underside of the fender with foil (from my hat) or metal screening. It'd be small, and the spec is something like 24" in each direction...but maybe.

The way to test all this is with an SWR bridge and some pretty sophisticated test equipment- to which I have secondary access. :  )

Maybe but the fender area is not going to make much of a ground plane.Let me know if I can help. I have an SWR meter for 2 meters.

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7 minutes ago, PbdBlue said:

Maybe but the fender area is not going to make much of a ground plane.Let me know if I can help. I have an SWR meter for 2 meters.

Agreed. I could line the bottom of the seat as well. Not exactly symmetrical, but might help. 

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This is great info!

Just had a thought:

Since many of these radios are dual band, why not use the 440 MHz (70-centimeter) band instead.  It gets out over terrain nearly as well as the 2 meter band.

The full wave antenna is 70cm, a half wave would be tiny.  And since the frequency wave is smaller, wouldn't the ground plain minimum area be smaller as well?

 

I do realize that the SDAR team has an informal goto frequency on 2 meter.  But easier to change the frequency used than to change the laws of physics.

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3 minutes ago, Sneeker said:

I do realize that the SDAR team has an informal goto frequency on 2 meter.  But easier to change the frequency used than to change the laws of physics.

Indeed, this is an option as well. Also a very slight edge on UHF for penetrating obstacles. Not much, but slight.

One of the reasons this is an option is because of the low-cost BaoFeng units.

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16 minutes ago, Bagstr said:

Installation Instructions.   Ground  Plain antenna to have minimum 3ft x 3ft metal surface.

 

True.

And!

 

The walkie-talkies we use are ground-plane dependent as well- they're designed to be used by a person holding them in a hand- which we don't do.

The question: Is there an advantage to using a higher-watt radio with a cobbled-together antenna system over using a smaller-watt HT stuffed into a backback, usually full of water?

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1 hour ago, paulmbowers said:

The walkie-talkies we use are ground-plane dependent as well- they're designed to be used by a person holding them in a hand- which we don't do.

   Therefore -  Suppose I clip a pull-away frame ground to the frame of my Hand-Held radio. You are telling me performance would improve? Hole in the bottom of the backpack, Grounding wrist strap on the handheld, friction / pull apart coupling at the seat.

https://www.bhphotovideo.com/c/product/850427-REG/Kingwin_ATS_W24_Anti_Static_Wrist_Strap_with.html

  Tested the FT270 frame and it is Powder Coated and non-conductive.  The Beltclip threaded 3 x.5mm hole is conductive to the frame.  As a Test; I will connect a Frame ground per above the the belt clip threaded hole and see if I improve performance.  This Week. 

  Although, many people use gloves as they PTT.

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Just now, Bagstr said:

   Therefore -  Suppose I clip a pull-away frame ground to the frame of my Hand-Held radio. You are telling me performance would improve? Hole in the bottom of the backpack, Grounding wrist strap on the handheld, friction / pull apart coupling at the seat.

https://www.bhphotovideo.com/c/product/850427-REG/Kingwin_ATS_W24_Anti_Static_Wrist_Strap_with.html

Nah. 

 

Tinfoil hat. 

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15 hours ago, paulmbowers said:

True.

And!

 

The walkie-talkies we use are ground-plane dependent as well- they're designed to be used by a person holding them in a hand- which we don't do.

The question: Is there an advantage to using a higher-watt radio with a cobbled-together antenna system over using a smaller-watt HT stuffed into a backback, usually full of water?

In the end the most critical point is the antenna and the match. Pushing more power into a crappy antenna will not yield much of an improvement and the receive side will be degraded so hearing responses from your buddy's 5 watt HT will be the same if not worse than your current setup. More power is really not the answer your'e looking for. IF you can get enough ground plane to tune a quarter wave below 2.0 SWR you will likely see some improvement but be aware that a quarter wave antenna has a more vertical radiation pattern meaning that most of the signal is directed upward instead of outward which is not ideal for your situation. A 5 watt HT connected to a properly tuned half wave antenna will far outperform a 25 watt radio connected to a badly tuned antenna. Will it be better than an HT with a duck? Maybe but I doubt by much. Also be aware that if the antenna match is bad it puts a tremendous strain on the output stage of the transmitter and could adversely affect it's service life. Some radios actually will inhibit transmission if the SWR is greater than 3 though I doubt the chinese radios have that feature. As mentioned unfortunately physics is physics. UHF is an interesting thought but the then all your riding buddies would have to switch as well. Just as an aside I was over at the CORE ride this past weekend in my RZR which has a 50 watt radio (running 25 watts) and a half wave with a large ground plane. I was able to hear and talk to CID several miles away in some pretty hilly areas. 

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  "In my RZR which has a 50 watt radio (running 25 watts) and a half wave with a large ground plane. I was able to hear and talk to CID several miles away in some pretty hilly areas. " 

    Was the CID on a bike or in the RZR,  i.e. 5watt or higher?

 

Standing-wave ratio (SWR) -- Sometimes called voltage standing-wave ratio (VSWR). A measure of the impedance match between the feed line and the antenna. Also, with a Transmatch in use, a measure of the match between the feed line from the transmitter and the antenna system. The system includes the Transmatch and the line to the antenna. VSWR is the ratio of maximum voltage to minimum voltage along the feed line. Also the ratio of antenna impedance to feed-line impedance when the antenna is a purely resistive load.

Impedance -- The opposition to electric current in a circuit. Impedance includes factors other than resistance, and applies to alternating currents. Ideally, the characteristic impedance of a feed line is the same as the transmitter output impedance and the antenna input impedance.

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On his bike. HT with an extended duck. On another note when I camp in the motorhome I have a half wave (with groundplane) base antenna mounted on a 30' flagpole. With that setup I can communicate with bikes that have ht\duck setups for 15 - 20 miles if the terrain is open. In the RZR my daughter has been able to talk to me (on the bike HT) from Sand Dam (Superstition) to Painted Gorge with no issue. It's really about good antennas more than power.

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16 hours ago, Bagstr said:

Will help but i don't think there's enough in the frame to provide an adequate GP. That's not a very good connection wire they are selling. At RF frequencies you would be much better off using a braided ground strap. 

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    Thank You Randy.   I will still try the grounding of my handheld transceiver to the bike frame.

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3 minutes ago, paulmbowers said:

 

 

Thank you Dr. Killjoy.

-_-

Yeah I know. Just strap a half wave antenna to your backpack:)

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Just now, Covered in Dust said:

This has worked great for me, I can hear the mothership clearly in my head at all times.

 

Electro Deflecto Unisex "Tin" Foil Hat One Size https://www.amazon.com/dp/B01I497JAM/ref=cm_sw_r_cp_tai_VNOBAb2E31198

 

Electro Deflecto Unisex "Tin" Foil Hat One Size

 

Covered in Voices

Isn't that what they wear at the Bombay Beach Club?

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19 minutes ago, PbdBlue said:

Yeah I know. Just strap a half wave antenna to your backpack:)

 

Antenna + Arai XD4 + Gaffer tape

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Paul -

I think you have used Smiley antennas in the past. If you still have one it might be interesting to try it out mounted to the frame of the bike in some fashion connected to your 25 watt radio. You can swap the connector to a PL-259 which might make fabricating a mount easier. Don't know if it will work but it might be worth a try. I have an extra one you can play with but if memory serves me it's tuned to 152 Mhz. They are rated for 50 watts max.

 

http://www.smileyantenna.com/product-p/14620.htm

http://www.smileyantenna.com/product-p/2=.htm

 

 

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