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New LID Question


WRWS304

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Good afternoon all, 

As a recently coordinated tech ham/gmrs LID, I had a couple of nagging questions that I wanted to ask help with before I spent too much time and money going in the wrong direction. I will also say I generally understand the concept of tuning an antenna for SWR, and the general rule that the more finally tuned an antenna is to a specific frequency, the more efficiency/performance one would receive on that frequency.

What I am attempting to do is have a home base station and mobile station that has the ability to cover (TX/RX) the following bands with only reasonable performance: 6m, 10m, 11m (CB), 2m (including MURS), 1.25m, 70m (including GMRS frequencies). With that said, I’m trying to figure out what the antenna situation would end up looking like if I am able to achieve this. I have a little-to-no interest in having my log cabin cluttered with unsightly antennas, or my vehicle looking like some Ham-Clampett wagon going down the road.  

I would like point out here that I understand that having any quality access to this many bands may end up requiring me to install what I consider to be an unreasonable amount of antennas. 

I digress. As I was doing research on the topic, I came back across the concept of using an antenna tuner to ‘tune’ your antenna to the frequency using. This reminded me of the stories of Elmers using an antenna tuner to tune a lawn chair for TX/RX on the 6m band.
 

Wouldn’t that ability to tune an antenna mean that I could get 1, 2 to 3 quality antennas mounted for my home base station and then with a combination of antenna switch and an antenna tuner, tune the antennas to whatever band I was using at the time? 
 

As for my mobile station, I am assuming I’m going to need 3 antennas to reasonably access and utilize the bands I mentioned, however, I was wondering if the same concept of 3 antennas + antenna switch + antenna tuner would apply for mobile stations that say they have ‘automatic antenna tuning’? 

Please forgive the long question post. Any clarification you could give would be outstanding. Thank you. 
 

Respectfully,

DS

 

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There are ways to minimize the number of antennas. I think you could get by with a couple of antennas but you’ll be compromising performance. But if you figure out where you want to concentrate your attention (which bands are most important) you can manage. 
An end fed half wave can work well for the HF bands without looking like a n NSA station. It’s just a wire strung up and blends into the background, but it stops at 10 meters. Or, if you’re willing to compromise performance a little more the Diamond BB7V handles HF and 6 m.
There are many decent multi band antennas. I would look for one for 2 meters, 1.25 meters and 70 cm, like the Comet cx333, but @marcspaz has had good success covering GMRS with a Diamond antenna. 
Otherwise you’ll need another dual band antenna for MURS and GMRS. 

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5 hours ago, WRWS304 said:

What I am attempting to do is have a home base station and mobile station that has the ability to cover (TX/RX) the following bands with only reasonable performance: 6m, 10m, 11m (CB), 2m (including MURS), 1.25m, 70m (including GMRS frequencies). With that said, I’m trying to figure out what the antenna situation would end up looking like if I am able to achieve this. I have a little-to-no interest in having my log cabin cluttered with unsightly antennas, or my vehicle looking like some Ham-Clampett wagon going down the road.  

Vehicle: Do you need multiple bands available at one time? Without diplexers (wide frequency separation, 2m vs 70cm, HF vs VHF) and/or duplexers (narrow frequency separation -- typically same band) you will only get one active band at a time.

A screw-driver type antenna may be suitable (unfortunately most seem to be mid-HF up to 6m) https://www.tarheelantennas.com/baby_tarheel

Yaesu has the ATAS-120 which covers mid-HF up to 2m/70cm [not 70m!] (2m/70cm is covered with the antenna all the way down) Problem: I don't think it works with generic up/down controllers, it was designed for a series of mobiles that contained built-in control logic [press menu TUNE, radio reduces power, goes into transmit mode, radio runs antenna up/down for minimum SWR]. I used one with an FT-100 (actually, started with predecessor ATAS-100 [rubber accordion boot handled length changes], changed to ATAS-120 [plastic outer tube slides over inner tube] when I moved to MI) on my Jeep Cherokee for 20 years -- until I rolled the Jeep two years ago.

Very few multi-band antennas exist, even Amateur-only, that include 1.25m. Heck, it is common for HTs that include 1.25m to run at reduced power (~1W on a 5W HT) due, I suspect, to the difficulty in tuning the antenna for 2m/1.25m/70cm at the same time. Kenwood seems to be the exception -- their (discontinued) HTs that had 1.25m ran it at full power (D74A, F6A). Yaesu VX-8DR "Tri-bander" (6m, 2m, 70cm) included 1.25m in the US version -- with max power 1.5W.

Home: Same question: multiple bands at once? Some off-center-fed-dipoles (OCFD) cover 40m/20m/10m/6m (but is going to be 66 feet long). The VHF/UHF bands are heavily mobile/HT oriented, and it is best to use vertical polarized antennas for those. HF/6m tends more to use horizontal polarization since signals bouncing off the ionosphere tend to be randomly polarized at the destination -- horizontal antennas being easier to support (consider, with the bottom at 35ft, that OCFD top would be at 100ft, and needs to be away from metal that it could couple to). Consider "stealth wire" -- https://www.dxengineering.com/search/part-type/wire/product-line/dx-engineering-stealth-antenna-wire for dipoles and similar. https://www.electronics-notes.com/articles/antennas-propagation/dipole-antenna/hf-multiband-fan-parallel-dipole.php Note the caution about harmonics -- 2m and 70cm are harmonic, MURS and GMRS are near harmonic -- but 2m and GMRS is not.

OTOH: a quarter-wave ground-plane whip for GMRS is only 6.3 INCHES, and about the same for the ground-plane radial wires. The low-loss coax will be more noticeable than the antenna itself.

FYI: MURS is NOT "2m" -> 1.9m, nor is GMRS "70cm" -> 64cm. And 2m/70cm antenna would have to a wide-band antenna, and that likely means antennas that don't have ideal SWR on any frequency... 1.5:1 would be great.

 

5 hours ago, WRWS304 said:

I digress. As I was doing research on the topic, I came back across the concept of using an antenna tuner to ‘tune’ your antenna to the frequency using. This reminded me of the stories of Elmers using an antenna tuner to tune a lawn chair for TX/RX on the 6m band.
 

Wouldn’t that ability to tune an antenna mean that I could get 1, 2 to 3 quality antennas mounted for my home base station and then with a combination of antenna switch and an antenna tuner, tune the antennas to whatever band I was using at the time?

The main purpose of an Antenna Tuner is to present a low SWR to the RADIO. It does not really change the behavior of the antenna.

Back in the days of power output TUBES tuning an antenna was not quite as critical. However, the power FETs used in modern radios can only absorb so much power which converts to heat before failing. The tuner lets the radio "see" a matched transmission line which allows the FETs to put out their full rated power (the better radios have safety circuits -- they /reduce/ power when the mismatch is higher than some level to keep the forward&reflected power under the ratiing). Radios with built-in tuners often can only tune a 3.0:1 ratio down closer to 1.0:1. External tuners (many of the LDG boxes) can handle 10.0:1 mismatches.

Note that tuners located at the radio end don't affect the SWR on the coax. High SWR in the coax can cause decomposition of the dielectric/insulator which could cause it to short-out (center conductor "melts" its way to the shield -- especially on bends/curves in the coax). Remote control tuners mitigate that, but... Tuners may also be "tuned" internally for specific frequency bands and might not even operate outside of those bands -- depends on the circuitry.

Most antenna switches are really meant for selecting different antennas for one radio. If you are trying to use the switch with one antenna and multiple radios, you will need one with very high isolation between ports. Otherwise you will have some power from the active transmitter leaking into the connection of an inactive radio, risking the receive circuits. You might have to operate at reduced power to counteract leakage.

 

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8 hours ago, WRWS304 said:

I have a little-to-no interest in having my log cabin cluttered with unsightly antennas

Unsightly antennas are bad. Put up only good looking antennas, the more the merrier! Your cabin will be gorgeous, and an envy of all neighbors. Your mother-in-law will be glad and will brag about your antennas on her facebook!

8 hours ago, WRWS304 said:

6m, 10m, 11m (CB), 2m (including MURS), 1.25m, 70m (including GMRS frequencies).

That's would be tough to cover these bands with one antenna. Tri-band 6m-2m-70cm antennas do exist, but lumping 10m, 11m and 1.25m would be difficult. Antenna tuners also exist but mostly down to 6m. I'm not aware of auto-tuner for 2m and shorter. If it exists, it's going to be expensive. There are manual tuners for 2m - 70cm, but KAF6045 mentioned losses in the coax. 11m-10m-6m could be covered with one antenna, 2m-MUSR-70cm-GMRS with another, and 1.25 is an outlier. Any antenna can receive, but if you want to transmit, you likely will need a dedicated antenna for it.

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Mobile or base, you are likely going to need at least 2 radios (possibly 3), a diplexer and best case, 3 antennas, if not more.

 

As far as antennas go, I am not aware of any antenna that 'works' on 2m, MURS, 1.25m, 70cm and FRS/GMRS.  Definitely none that cover all that AND HF.  My opinion, regardless of what base antenna and tuner combo you use, you're not getting a single antenna to 'work' on all of those bands.  I've tried.  With decades of experience and a massive network of smart people, it's just never happened.  Sure, a tuner will make the radio happy, but it will be like a dummy load... it's not going to radiate. 

 

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KAF6045 - what a wealth of information. Thank you for taking the time to share.
 

The idea would never be to use more than one frequency at a time on the road or at home base; rather the different bands would be about keeping my options open to scan and transmit.
 

Thank you for the recommendation. I’ll check them out!

DS

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27 minutes ago, WRWS304 said:

Marc,

thank you for sharing your experience of trial and error. It seems like I’m going to need to have 3 antennas on the vehicle and 3 on my home base station. If I can get reasonable use out of the bands I mentioned with that set up, I will be happy


 

DS

You might also see this post which describes the Comet 2x4. That’s an antenna designed to cover a wide range of frequencies for emergency services. The advertised range covers 2meter, MURS, 70 cm, and part of GMRS:

 

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I just posted the results of doing SWR sweeps on both the CA-2x4SR and a Larsen 150/450/800 on my truck yesterday in that other thread.

I also have two triband base antennas on my house and I swept them as well.  Here are the max SWR values on each band:

Antenna 2m 1.25m 70cm GMRS MURS 6m
Diamond V2000A 1.3 4.1 1.42 1.43 3.1 2.55
Comet CX-333 1.4 1.1 1.76 2.2 4.6  

The CX-333 is a 2m/1.25m/70cm antenna and does well on all three of those bands.  The SWR is above 2:1 at 151 MHz and well over 3:1 on 154 MHz, so not usable for MURS.  SWR is between 2:1 and 2.2:1 at both 462 and 467 MHz so not great for GMRS but probably OK for limited use.

The V2000A is 6m/2m/70cm.  On 6m SWR starts at 2.55:1 at 50 MHz but is under 2:1 from about 50.65 through 54.  I have mine tuned so the lowest SWR (1.12:1) is around 53 MHz.  SWR is good on GMRS simplex and repeater inputs and is under 2:1 on 151 MHz but up around 3:1 on 154 so would be usable on some of the MURS frequencies.

As others have stated, you are not going to find one antenna that will do "6m, 10m, 11m (CB), 2m (including MURS), 1.25m, 70m (including GMRS frequencies)".  You also have to keep in mind that 2m doesnt "include MURS" nor does 70cm "include GMRS"; the frequencies are enough different that an antenna resonant for the ham bands may perform very poorly on MURS/GMRS.

There are a number of local hams who use the IMAX-2000 (which is a CB antenna) for 10m so that would be an option for those.  Diamond also makes a 6m/10m vertical.

One unrelated comment ... you must not be using "LID" the way I understand it to mean.  Hopefully you aren't one!  ?

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Thanks WRCI350! I am beginning to get a better lay of the land.

Sounds like I will need to run 3 antntenas min. with mobile and base, and maybe even end up dropping the 6 and 1.25 meter bands to make the mobile project work. 

As for LID, I was told it meant 'Licensed Idiot'...and as a newbie I am relatively ignorant on the topic...and now licensed! LOL 

I have used radio comms in the military for two decades now, however it's always been spoon fed to myself/the team by the techs; 'here's your radio, here's your beacon, the a/b freqs and here's a Sat phone',  kind of thing.

DS

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24 minutes ago, WRWS304 said:

Thanks WRCI350! I am beginning to get a better lay of the land.

Sounds like I will need to run 3 antennas min. with mobile and base, and maybe even end up dropping the 6 and 1.25 meter bands to make the mobile project work. 

As for LID, I was told it meant 'Licensed Idiot'...and as a newbie I am relatively ignorant on the topic...and now licensed! LOL 

I have used radio comms in the military for two decades now, however it's always been spoon fed to myself/the team by the techs; 'here's your radio, here's your beacon, the a/b freqs and here's a Sat phone',  kind of thing.

DS

I would suggest that you get some experience and education before building a rolling NSA station designed to cover every frequency.  There might really not be any need and by adding all of the frequencies and limiting the number of antennas you want as bristles on your vehicle, you are constraining yourself to compromises somewhere.  Why do you want to cover MURS?  Why do you want to cover 1.25m?  Are they truly important to you?  Do you need to transmit on them all or just be able to monitor them?  Especially for mobile use you probably don't need to cover that much. In any kind of communications plan for emergency use you will probably want to restrict your activities to one or two specific frequencies or you stand the risk of never finding someone.

Another thought is that there are antenna systems where you swap out the element to concentrate on a single band at a time. They are available for 80 meters through 6 meters and can even be combined for greater versatility.  They're sometimes called Ham Sticks. Shark is one of the vendors carried by Gigaparts:

https://www.gigaparts.com/nsearch/?lp=SHARK

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56 minutes ago, Sshannon said:

Another thought is that there are antenna systems where you swap out the element to concentrate on a single band at a time. They are available for 80 meters through 6 meters and can even be combined for greater versatility.  They're sometimes called Ham Sticks. Shark is one of the vendors carried by Gigaparts:

The Outbacker series uses movable taps to change bands... Probably less messy than hauling a golf-bag full of HamSticks. Unfortunately the Perth Plus appears to have been discontinued (I have one, along with the Alpha Delta OutPost tripod mount -- for years it was the only way I could get on the air from my apartment in Sunnyvale). The regular Perth only runs up to 10m -- the Plus included 6m and 2m. Some of the rest of the series have options that go up to 6m.

Random searching...

https://www.dxengineering.com/parts/cma-uhv-6

https://www.dxengineering.com/parts/dmn-cr8900a

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  • 2 weeks later...

Good afternoon!

Thanks again folks for all the answers! It has been awesome to have a community willing to help fill in knowledge gaps for those of us new to the hobby. 

Figured I would share for posterity's sake what I ended up with for my SUV and for my home stations. If the blog is still open for comment on I'll report back with how it all works.

Mobil

  • TYT TH-9800D Plus, Quad-Band, Cross-Band, 50W Mobile Transceiver
  • Browning BR-137 Tri-Band High Gain 22 inch Antenna (VHF 136-174 UHF 380-520 & 698-960 MHz) (Mostly for MURS, Marine and GMRS)
  • President Electronics New Virginia Antenna (CB / 10m)
  • Diamond Original CR320BNMO Triband Antenna (2m, 1.25m, 70cm)
  • Anteenna TW-103 3 Position Coaxial Switch HF/VHF/UHF
  • Bolton Technical LMR 600 Equivalent Ultra Low-Loss Coax

Homebase

  • TYT TH-9800D Plus, Quad-Band, Cross-Band, 50W Mobile Transceiver
  • BTECH RPS-30M 30 Amp Regulated Universal Compact Bench Power Supply
  • Yaesu SMB-201 Base Cooling Fan Assembly 
  • Solarcon IMAX-2000 Base Station Vertical Antenna (CB / 10m)
  • CX-333 CX333 Original Comet Tri-Band Base Antenna (2m/1.25m/70cm)
  • Nagoya NMO-200C 38.5" Antenna NMO Mount Dual Band (VHF 155, UHF 460MHz) (GMRS, MURS)
  • TRAM 1465 Land Mobile Base Ground Plane Kit
  • Bolton Technical LMR 600 Equivalent Ultra Low-Loss Coax

 (Yes, I'm on a budge, and yes I am confident I will upgrade my radios, antennas, etc. in the future)

THANKS! 

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On 4/20/2023 at 7:05 PM, WRUU653 said:

Well at least you’re starting out slow.? you may be on a budget but it’s a good one. Good luck and pictures please when you’re set up. 

Point taken ? I guess I learn by doing. I was mostly prepping for the ‘cheap Chinese radio’ and ‘get a REAL radio’ comments. I’ll spend less on both setups than a lot of HAMs spend on one radio. I am mostly concerned with a) monitoring and b) having the capability to TX with family/etc. in an emergency situation. I’ve been licensed for a while now and still have never felt the need, or desire, to join into conversations I’ve overheard. 
 

DS

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