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Musing on equipment choices...


wayoverthere
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Started in this section, since it's a ham/GMRS overlap topic. Since i haven't figure managed to work in testing for my ticket, it's still pondering at this point. But that said...

 

Looking at having 2m, 70cm and GMRS in my truck, and since GMRS is fairly dead here, I think the ham side will get more focus.I suspect there isn't a part 95 certified holdover that will cover all 3, which leans toward having 2 radios . I know there will be antenna considerations as well.

  • Option 1: Vertex VX-4207 (covers 400-470mhz, and part 95a, yeah!) that i recently acquired, and a single bander for 2m. Leave Btech GMRS 50x1 as base station, add a dual band (no need for remote head) there at some point.
  • upside of this is more power in the single band 2m, compared to most dual band, and the singles are generally less expensive. also, not needing a remote head on the dual band at home means a little less expensive in general.
  • downside is finding space for both radios; i don't see any remote head options in new single band radios, though i'm there seems to behit or miss possibilities on the used LMR side of things.
  • Option 2: Vertex as base, with a single bander for vhf; throw the Btech in the truck, and pair it with a dual band radio that offers remote mounting.
  • upside is saving space in view, and the home side of the equation is less expensive.
  • downside is the truck side is a bit more expensive.

 

Overall, dash real estate being an issue, (and how little time I spend in the truck the past year or so) I'd lean toward the second option, but I'm open to thoughts/ideas/suggestions/other things I haven't considered. It's really just a 'thinking out loud' stage right now.

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Well on the antenna side for the mobile you can look at the following:

 

https://cometantenna.com/wp-content/uploads/2013/09/CA-2x4SR.pdf

 

I have a buddy at work with one installed on his pickup truck. The SWR is under 2:1 where he operates on GMRS when I checked it for him. The match is better towards the Ham band on 70cm. On VHF the match is really good on the Ham 2M band and on the 5 MURS channels.

 

The trick with this antenna is it needs a really good ground plane since it's a 5/8 wave design.

 

If you don't want to go that route then get a good Ham dual band antenna and a cheap simple 1/4 wave for GMRS. A 1/4 wave GMRS antenna is about 6 inches tall.

 

By the way 1/4 wave antennas have a wide bandwidth and the radiation pattern is much broader giving better coverage when in hilly terrain. Some people go with a 1/4 wave for GMRS for just that reason.

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For antenna I have a Larsen NMO150/450/758 that does well on the ham bands and excellent on GMRS. It's a commerical antenna, so it is designed for commercial frequencies, but it is acceptable for HAM use. It also has a spring on it and survives parking deck hits and car washes.

 

As for radios, keep in mind, by law you have to have a RF exposure evaluation if you exceed 50w in VHF. For reference, at 50W you need 3.5' distance for a controlled environment (ok as long as you aren't talking more than 50%) and 7.5' in uncontrolled.

 

The two radios would work if you tossed in a diplexer. Part 90/95 UHF and a separate VHF. You will have problems with frying each other if you use two UHF radios, you can't get enough seperation to make it work unless you use an expensive high/low pass filter or commercial diplexer, even then it's not ideal.

 

You could also look at Kenwood commerical stuff, you can run two RF decks on one head, but it's not cheap.

 

There are also some quality Part 90 dual band radios that will work well, though they don't follow the letter of the law. I have a CS800D in my car, though I don't use GMRS in my truck, it's dead here.

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For antenna I have a Larsen NMO150/450/758 that does well on the ham bands and excellent on GMRS. It's a commerical antenna, so it is designed for commercial frequencies, but it is acceptable for HAM use. It also has a spring on it and survives parking deck hits and car washes.

 

As for radios, keep in mind, by law you have to have a RF exposure evaluation if you exceed 50w in VHF. For reference, at 50W you need 3.5' distance for a controlled environment (ok as long as you aren't talking more than 50%) and 7.5' in uncontrolled.

 

The two radios would work if you tossed in a diplexer. Part 90/95 UHF and a separate VHF. You will have problems with frying each other if you use two UHF radios, you can't get enough seperation to make it work unless you use an expensive high/low pass filter or commercial diplexer, even then it's not ideal.

 

You could also look at Kenwood commerical stuff, you can run two RF decks on one head, but it's not cheap.

 

There are also some quality Part 90 dual band radios that will work well, though they don't follow the letter of the law. I have a CS800D in my car, though I don't use GMRS in my truck, it's dead here.

 

Thanks for the food for thought, and the reminder that i need to give the antenna side of the equation a little more thought as well.  The part 90 route may end up being the winner (gmrs is mostly pretty dead here too, but nice to have the option), and the RF exposure aspect was something i hadn't thought about, but definitely need to...that aspect also makes the dual band mobile/single bands at base sound better, though getting the antenna OUTSIDE will be a necessity.

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Thanks for the food for thought, and the reminder that i need to give the antenna side of the equation a little more thought as well. The part 90 route may end up being the winner (gmrs is mostly pretty dead here too, but nice to have the option), and the RF exposure aspect was something i hadn't thought about, but definitely need to...that aspect also makes the dual band mobile/single bands at base sound better, though getting the antenna OUTSIDE will be a necessity.

Yea, the most overlooked thing GMRS and HAM operators forget is power levels and RF exposure. Even if you are NOT required to maintain a RF exposure calculations, you must still maintain safe distances and power levels.

 

IMO, stay away from Anytone, I have their 878 and it has some serious desensitize issues, even after being replaced under warranty. They claim part 90, but I'd avoid them.

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  • 1 month later...

Couple minor updates since last month; passed test for tech as of a couple weeks ago, and finally got some things ordered to expand my shack.  have a couple new antennas inbound for base (gp1) and mobile (ca2x4sr, nmo), and a dual band radio (icom 2730a) for the truck. still pondering the 2m side of base, leaning toward just adding a single bander for that (likely yaesu or icom), but not set in stone yet.

 

on research, my town appears to lump ham antennas with other telecommunications facilities, requiring professional engineering reports to get the required permits, and yearly certification that it's still in operation.  with that in mind, i went on the smaller side  for the base antenna so i can attic mount it and avoid all the messing with the city and permits and such.

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Run two radios and two antenna's.  You are not going to find an antenna that will properly do all three and have any gain. (only option is a mobile discone).

The other issue you run into is there are no ham radios that are natively GMRS radios and dual band, unless you have stacks of money and buy a Motorola APX 7000 or 8000 which are dual band and will cover all three.

 A modified ham radio wouldn't be legal on GMRS anyway. 

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Run two radios and two antenna's. You are not going to find an antenna that will properly do all three and have any gain. (only option is a mobile discone).

The other issue you run into is there are no ham radios that are natively GMRS radios and dual band, unless you have stacks of money and buy a Motorola APX 7000 or 8000 which are dual band and will cover all three.

A modified ham radio wouldn't be legal on GMRS anyway.

It will be running two radios either way, it's just a question of combining 2m and 70cm with gmrs separate, or gmrs with uhf, and 2m separate. (Leaning toward the first option, eventually..will probably go without 2m for now).

 

I'm already set with gmrs radios and antennas for both base and mobile (btech/Midland), and the vertex is 95a certified. Not holding my breath that the GP1 will be good for gmrs frequencies, but figure i'll check.

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If you go that route, two radios, the separate 2m and combo Ham 70cm with GMRS is a recommendation. All of the Kenwood commercial HT’s radios I have all will program down into the repeater section of the Ham 70cm band and most of the simplex section. So I can use just one radio for both services so long as it’s on UHF. When I’m not going to the gym I go for long walks so having just one radio is a big convenience for access to both services.

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If you go that route, two radios, the separate 2m and combo Ham 70cm with GMRS is a recommendation. All of the Kenwood commercial HT’s radios I have all will program down into the repeater section of the Ham 70cm band and most of the simplex section. So I can use just one radio for both services so long as it’s on UHF. When I’m not going to the gym I go for long walks so having just one radio is a big convenience for access to both services.

thanks for the input. 

 

haven't even dug into the handheld side any more yet, but i think i'm covered okay there between 3 vertex UHF HTs and 2 dual band baofengs.

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It will be running two radios either way, it's just a question of combining 2m and 70cm with gmrs separate, or gmrs with uhf, and 2m separate. (Leaning toward the first option, eventually..will probably go without 2m for now).

 

If you go that route, two radios, the separate 2m and combo Ham 70cm with GMRS is a recommendation.

 

I've got a similar situation/setup (want to purchase a separate 2m Ham radio/antenna).  So I have two questions:

 

1 - What radio/antenna would you suggest for the 2m Ham setup (am somewhat price conscious)?

 

2 - Existing 70cm antenna is tuned for GMRS, not Ham.  How does the combo 70cm Ham and GRMS antenna work out?

 

Thanks for any advice.

 

...

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I've got a similar situation/setup (want to purchase a separate 2m Ham radio/antenna).  So I have two questions:

 

1 - What radio/antenna would you suggest for the 2m Ham setup (am somewhat price conscious)?

 

2 - Existing 70cm antenna is tuned for GMRS, not Ham.  How does the combo 70cm Ham and GRMS antenna work out?

 

Thanks for any advice.

 

...

 

Most antennas are pretty wide band on 70cm. I have used a 460MHz quarter wave whip, a Larsen 150/450/758 tri-band and a Larsen 2/7sh with good results.

 

From someone on radioreference, he swept a Larsen 2/70sh drilled in a new silverado 16" from the back of the cab:

http://i.imgur.com/fOoyGjk.jpg?1

 

As you can see, it is more than adequate for 70cm ham and GMRS use. I noticed the same for the Larsen 150/450/758, and my VNA sweep on the 1/4 wave whip was under 1.6 across (410-490) with the lowest centered on 450ish.

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Is there such a thing as a legal Ham radio?

 

I contacted Midland about their DBR2500 dual-band Amateur radio to see if it was Part 90 certified, and they said no, but offered no information about any other type of certification. 

 

I bought Midland GMRS radios because i believed them to be certified for GMRS.  Is there no such animal for Ham?

 

Thanks.

 

...

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Amateur radios are part 97 which has different requirements than the other parts. You won't find a Part 95 and Part 97 radio. A lot of the Part 97 radios can be modified to operate out of band for both MURS and GMRS frequencies but they are not authorized to operate on those frequencies. That doesn't mean there aren't a lot of them that do, they are just not in compliance when they do.

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Is there such a thing as a legal Ham radio?

 

Pretty much any radio that can transmit and receive within the FCC authorized ham frequencies is "legal." This is because amateurs are allowed to build their own equipment and provided they don't cause any interference issues, they are "legal" to use.

 

But sadly, probably 95% or more hams have been "appliance operators" these past thirty years or so.

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  • 2 weeks later...

I have both ham and GMRS.

I use my 2M/70cm ham antennas with no problem on my Wouxun 805G radio.

The SWR is well below 2:1 which is good enough for me. (That's less than 10% reflected power.)

Of course, I do not connect the ham and GMRS at the same time.

 

My ham radio is a Yeasu mobile 2M/70cm and I don't usually use it while under way.

I use it more at camp but often do not get any replies on the repeaters.

Truthfully it's been rather useless.

 

The GMRS is very useful for vehicle to vehicle comms while traveling together.

Most of our fishing and camping buddies (and my wife) do not have a ham license. 

So GMRS or FRS is the way to go.

 

Vince

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I've got a similar situation/setup (want to purchase a separate 2m Ham radio/antenna). So I have two questions:

 

1 - What radio/antenna would you suggest for the 2m Ham setup (am somewhat price conscious)?

 

2 - Existing 70cm antenna is tuned for GMRS, not Ham. How does the combo 70cm Ham and GRMS antenna work out?

 

Thanks for any advice.

 

...

I'll have to recheck the swr on the one on the truck; it's a tram browning 5/8 over 5/8 uhf, and it's been enough to get 5 watts from the uhf handheld to a repeater 30ish miles away pretty solid. Been running it with the mxt115 for gmrs.

 

I know when i checked see on the midland 3db gmrs antenna on 446.000, it showed like 2.4, so not so good there.

 

Current state of things is the vx4207+icom 2730a as my base, on separate antennas (midland 3db and comet gp1 dual band). On the mobile side, the mxt115 and a uhf vertex handheld take turns with the tram browning antenna.

 

In retrospect, what I spent on that (and the other 2) uhf vertex I probably could have gotten a decent dual band yaesu or something, but live and learn.

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So I was thinking about getting the Midland DBR2500 dual-band (70cm and 2m) radio.  It is 25w, 144-148MHz VHF and 420-450MHz UHF.

 

I was thinking about getting a Tram 1470 pre-tuned dual-band antenna to go with it (144-148 and 430-460), and some 36' of RG-8X cable.

 

Does anyone have any experience with this or a similar setup?

 

Thanks.

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My nanonva says my Comet triband base antenna is better for 1.25m and 70 and 65cm than 2m.  Still around 1.8:1 on 2m, so its good everywhere. 

that would be a nice bonus, and would play very well into 2 radio, 70/65cm and 2m setup, especially once i get the comet into a better location than set up on a tripod in my office.  i think nanovna will be going onto the shopping list in the near future....probably joined by a little better swr meter as well.

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You really only need a swr/power meter in addition to a nanonva to show you the power output and reflected power going back into your final without doing the math or if you suspect your radio isn't up to spec.  

Advantage of the nva over a swr meter alone - nva not only tells you the relative tuning of the antenna and feed line, if you need tuning, it tells you which way to go.  SWR meter only tells you whether you are in range of your goal, not whether to lengthen or shorten your antenna element to achieve your goal.

 

ETA: I wish 2 radios was enough, LOL

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You really only need a swr/power meter in addition to a nanonva to show you the power output and reflected power going back into your final without doing the math or if you suspect your radio isn't up to spec.

 

Advantage of the nva over a swr meter alone - nva not only tells you the relative tuning of the antenna and feed line, if you need tuning, it tells you which way to go. SWR meter only tells you whether you are in range of your goal, not whether to lengthen or shorten your antenna element to achieve your goal.

 

ETA: I wish 2 radios was enough, LOL

I know, I'm just playing in the shallow end for now with 2m/70cm/gmrs, and the reality is a bit more than 2 when I start counting, especially the handhelds.

 

Edit: I should really stay off eBay. Found a couple deals I couldn't pass up on a couple more vertex...another evx539 (in g6 split, this time, with charger), and a g6 split vx-p824..no charger, but it takes the same battery and charger as the 924 I have already.

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