Let's talk about 6m FM

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KJ6NWU

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There are at least a dozen hams running 6M FM mobile here in the Tampa area. I often enjoy a QSO on my morning drive. I've experienced a few surprise openings to Texas and Louisiana in the early evening.
 

w8prr

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I love 6 meters no matter what the mode. The difference between FM and SSB is the same as any other VHF/UHF band. One is for weak signal, FM is not. I really like old police/fire radios (have a 1957 Ford fire engine) and have Motorola, GE, Aerotron, Johnson, Comco and Regency rigs on 52.525.
Just another way to play radio.
 

Kb2Jpd

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I'm wanting to get into 6m FM pretty bad. I've located a nice commercial rig that will work 6 & 10 meters. How many of you guys work 6m FM? I'm just curious on what kind of antenna you're using.



I'm looking a the Arrow 6m beam antennas. I already have a rotor & associated hardware. My current tower setup will have me a little over 30 ft. AGL. Since it's FM, would a vertically polarized beam work better than a horizontal? I know 6m operates alot like HF, which favors a horizontal beam. Or so I'm told.



Anyways, any advise is greatly appreciated.



Hi from Adam Kb2Jpd in Brooklyn New York

There is a ham selling on eBay the old Motorola Syntor radios that cover 6 M and 10 M with 100 watt output. He will program specific frequency upon request.

I used one to create a remote base for a UHF repeater. Worked great. Just remember it is a 100 watt rig so beef up the electrical system, batteries and alternator.
 

W6SAE

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On a related note...

If there are any 6-meter FM aficionados from the San Francisco Bay or Sacramento Valley areas reading this, I'm going to be activating a summit for Summits On The Air (SOTA) the day after tomorrow (Thursday, May 12 11:00 a.m./1800 UTC) and would love to log a few 6-meter FM contacts. I'll be on Sulphur Springs Mountain, above Vallejo and should have a pretty good reach into the Bay Area and the Valley. I have yet to make a 6-meter contact since I bought my Wouxun KG-UV5D (6m/2m) several months ago. I'll be on 52.525 MHz.

I'll also be attempting 70-cm (446.000), with 146.520 closing the day out--that's where I'll probably log most of my contacts. I welcome any contacts, regardless of whether or not you're into SOTA.
 

902

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I'm not picking on anyone, but I've had some bad experiences with remote bases on 52.525.

There were some guys who were doing this kind of thing in St. Louis back 20 years or so, and how they were doing it was annoying (they were not annoying, but how they set up their system was, if that makes sense). Thankfully they got bored with it and took it down. There's a good way and a not so good way to put up a remote base on 52.525.

Just some general things on remote bases on 52.525 -
Make sure your remote base can be controlled on and off. I use 52.525 MHz quite a bit. One of the scourges of the band are local conversations on a 2 meter or 440 repeater being broadcast out on the simplex frequency - often with hang times, courtesy tones, and IDs. The chatter usually doesn't leave pauses and pretty much kills the frequency when the band is open to wherever part of the country or world. Reason being, 52.525 is simplex. When the local chatter is being broadcast on it, it's not listening to anything until the chatter stops, the beeps and boops are finished, and the carrier drops. Until that happens, no one can speak back to whomever is on the system. People don't think there's activity and they just keep chattering. It's a vicious cycle.

Strategies for success:
  • No boops/boops/talking controllers/or "hang time" on the link - EVER! The transmitter should drop out immediately after someone unkeys to give the stations on the frequency a chance to respond. If there's a need to ID the system (and the stations themselves aren't doing that), a CommSpec ID-8 that keys up lightly with CW on the voice transmissions is the least intrusive way of doing it.
  • Leave VERY LONG pauses while the link is activated. 52.525 is usually a frequency that's left on in the background and ops may be within earshot of the speaker, but not within reach of the mic to jump in.
  • Have a 60 second time-out timer on the link. If there are long-winded transmissions on the host repeater, they kill the remote frequency during band openings. They also kill your PA (I've replaced Syntor-X PAs because of long keydowns before - parts actually melt and flow off the board because it can get so hot). Use lots of fans on that thing. It's not meant for continuous duty.
  • Maybe the best way to run the remote base is to always have the receiver on (with repeater receiver priority and the option to disable the remote) and always have the link transmitter off until there's someone you want to make contact with.
  • If the repeater owner or club wants something that's up full-time, what they really want is a coordinated repeater on a coordinated repeater frequency, not a remote base on 52.525.
 

Kb2Jpd

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I'm not picking on anyone, but I've had some bad experiences with remote bases on 52.525.



There were some guys who were doing this kind of thing in St. Louis back 20 years or so, and how they were doing it was annoying (they were not annoying, but how they set up their system was, if that makes sense). Thankfully they got bored with it and took it down. There's a good way and a not so good way to put up a remote base on 52.525.



Just some general things on remote bases on 52.525 -

Make sure your remote base can be controlled on and off. I use 52.525 MHz quite a bit. One of the scourges of the band are local conversations on a 2 meter or 440 repeater being broadcast out on the simplex frequency - often with hang times, courtesy tones, and IDs. The chatter usually doesn't leave pauses and pretty much kills the frequency when the band is open to wherever part of the country or world. Reason being, 52.525 is simplex. When the local chatter is being broadcast on it, it's not listening to anything until the chatter stops, the beeps and boops are finished, and the carrier drops. Until that happens, no one can speak back to whomever is on the system. People don't think there's activity and they just keep chattering. It's a vicious cycle.



Strategies for success:

  • No boops/boops/talking controllers/or "hang time" on the link - EVER! The transmitter should drop out immediately after someone unkeys to give the stations on the frequency a chance to respond. If there's a need to ID the system (and the stations themselves aren't doing that), a CommSpec ID-8 that keys up lightly with CW on the voice transmissions is the least intrusive way of doing it.
  • Leave VERY LONG pauses while the link is activated. 52.525 is usually a frequency that's left on in the background and ops may be within earshot of the speaker, but not within reach of the mic to jump in.
  • Have a 60 second time-out timer on the link. If there are long-winded transmissions on the host repeater, they kill the remote frequency during band openings. They also kill your PA (I've replaced Syntor-X PAs because of long keydowns before - parts actually melt and flow off the board because it can get so hot). Use lots of fans on that thing. It's not meant for continuous duty.
  • Maybe the best way to run the remote base is to always have the receiver on (with repeater receiver priority and the option to disable the remote) and always have the link transmitter off until there's someone you want to make contact with.
  • If the repeater owner or club wants something that's up full-time, what they really want is a coordinated repeater on a coordinated repeater frequency, not a remote base on 52.525.



We did. The type of repeater controller really helped. 52.525 never heard a beep nor an ID from our setup.

Just was a real pain to find a 6M/10M antenna suitable for the hostile environment of up in a 35 story skyscraper.

Comet had leaky radomes. Always had to do some servicing after a good snowstorm. The wind pushed moisture into the inside of the Antenna and the stupid Japanese designers never thought to coat the copper elements against water.
 

W5KVV

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Well, if any of you guys are ever in my neck of the woods, my Motorola Maratrac is always scanning. It's been running for almost 3 years and so far I've had one good qso on it.

I'd love to get more use out of it!
 

902

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We did. The type of repeater controller really helped. 52.525 never heard a beep nor an ID from our setup.

Just was a real pain to find a 6M/10M antenna suitable for the hostile environment of up in a 35 story skyscraper.

Comet had leaky radomes. Always had to do some servicing after a good snowstorm. The wind pushed moisture into the inside of the Antenna and the stupid Japanese designers never thought to coat the copper elements against water.

I did similar. Once upon a time, I had a 6 meter repeater on a 32 story high rise in NJ. The Diamond/Comet class of antennas were a horror show with wind and lightning leaving remnants that were like bent clothes hangers. Not the right equipment. A DB201 or (if you can find them) the old style 35 or 43 MHz paging antennas cut to frequency were best.

On sending a repeater out on to 52.525, hearing beeps and boops is only part of the problem. The other thing is sending a local conversation out for TENS OF THOUSANDS of square miles with little chance for people to break in or use the frequency independently of the conversation. Just don't do it! It destroys the frequency. Someone in Indianapolis hearing about traffic on the Southern State is not thinking, "wow, the band is open," he's thinking "knock it off so I can make contacts," Putting a full repeater up would serve the community so much better - and leave simplex be simplex.
 

SCPD

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For the life of me I could never understand the philosophy of putting a repeater on low band VHF frequencies. Maybe in the 1950's or 60's they made some sense, when technology was still low banded-- but with all their limitations (ie; propagation, antenna size----) they make about as much sense as 75 metre repeaters today. Low band remotes, yes, but leave the repeats to the high band VHF and UHF's. If I am offending anyone, I would love to hear their good argument for 29 and/or 52 Mhz repeaters-- I can come up with none myself.
.
...................CF
 

902

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For the life of me I could never understand the philosophy of putting a repeater on low band VHF frequencies. Maybe in the 1950's or 60's they made some sense, when technology was still low banded-- but with all their limitations (ie; propagation, antenna size----) they make about as much sense as 75 metre repeaters today. Low band remotes, yes, but leave the repeats to the high band VHF and UHF's. If I am offending anyone, I would love to hear their good argument for 29 and/or 52 Mhz repeaters-- I can come up with none myself.
.
...................CF

Well... my former 6 meter repeater was split site. At the hub, I had a GE voting comparator and in the periphery, I had a few Hamtronics 6 meter receivers and 902 MHz link transmitters. It worked exceptionally well, but I retired and moved. I couldn't find anyone who could be granted access to some of the sites, and much of the hardware came with me. But the actual rackspaces were quite small. I did not use a duplexer at all. I chose 6 meters because of the terrain. 440 simply didn't work well. 6, on the other hand, hugged the ground. Even the state patrol agreed (although now they're higher in frequency, themselves).

A now-retired employee of the Garden State Parkway in NJ ran their radio shop and sent a handful of 6 meter receivers down their microwave backbone to a central comparator. That comparator sent audio and E&M keying up and down the state to 6 meter transmitters that hopscotched between two output frequencies 20 kHz apart, but kept the same input. When transmitter A became noisy, switch to transmitter B, and then back to A as you rode the GSP to go "down the shore." The 80s and 90s were a dream with that system. People in Northern NJ could talk to people in Southern NJ (when we were paying big telephone bills, that concept via VHF amateur radio was huge). Sure, you can say, "We do lots of linking now," but I haven't ever seen anyone else cover an entire state with two outputs and one input. Rather, one conversation brings up just about every available frequency pair (and in some cases, one conversation can bring up just about every repeater of a certain type all around the world). That's terribly inefficient.

As for 10 meter repeaters, once upon a time, I belonged to a New York City area repeater club. This was 37 years ago, not any of the much more recent 10 meter repeater implementations. It was a big novelty, actually. If you were a General, you could use a certain CTCSS tone (5A?) which would activate logic that would send you over 2 meters AND 10 meters. The 10 meter audio was always coming into 2. We would have regular conversations with stations in New Mexico and even as far as Israel and Japan. In the days when the FCC was like Coyote vs. Roadrunner in administering ham tests (it wasn't always "easy" and encouraging to upgrade, the questions used to be a secret and would change when they were published by a fellow named Dick Bash), a lot of people were encouraged to upgrade and get on HF. I even bought a Comtronix FM-80 so I could get on 29.6 (and worked Japan from my house with 10 W on 10 m on a Cushcraft Ringo vertical).

So, the best arguments I can offer are:
1) much greater area and efficiency of coverage for the investment in equipment, and
2) incentives in encouraging individuals to upgrade.

Not sure how relevant either are in this connected time, but they certainly were valid "back in the day" not so long ago.
 

902

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As always amazing story and knowledge given. I would be happy just work Japan you did it only using 10 watts....wow!
Yeah, and I was only 9.3 mi. east of you when I did it! I do have to say it was 1980 and there was a lot more activity on 10 FM at the time. The popular thing was converting CB radios to 10 meters, and people were also modifying them with varactor modulators to make them do FM. There were a ton of "CB-to-10" articles in 73 Magazine.

You can still convert a CB radio to 10 meters, especially if it's a sideband radio.
 
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SCPD

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A great story, 902 !, and that sounded like a system you can be very proud of. I think my question centre'd more on the state of the art today... and especially how it effects things when setting up systems on .525-- Personally I have a great affinity for low band VHF, and for those very reasons you enumerated.
.
It must have been the practical side of me kicking in, when I asked that question- Everything that can possible be done with low band is now done with the higher frequencies, and so, so much better - no skip interference, reasonable antennas- but on the other hand, the DX makes ham radio exciting, No? I love open remote bases outputting onto simplex, and as long as the repeaters stay off the simplex channels, I say "go for it"-- (Though I still think UHF is better for the day to day stuff......:) -- thanks again...
.
...................................CF
 

k8krh

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Interesting from years ago.
6 meter fm is still around here linked into 2 meters. 1 ten meter repeater but no idea how it is going , 35 miles away from here.
I remember someone use to convert those cb radios to 10 meters fm mostly , believe it was the wireman, sold hundreds of them, would be fun today.
DOCTOR 795
 

902

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A great story, 902 !, and that sounded like a system you can be very proud of. I think my question centre'd more on the state of the art today... and especially how it effects things when setting up systems on .525-- Personally I have a great affinity for low band VHF, and for those very reasons you enumerated.
.
It must have been the practical side of me kicking in, when I asked that question- Everything that can possible be done with low band is now done with the higher frequencies, and so, so much better - no skip interference, reasonable antennas- but on the other hand, the DX makes ham radio exciting, No? I love open remote bases outputting onto simplex, and as long as the repeaters stay off the simplex channels, I say "go for it"-- (Though I still think UHF is better for the day to day stuff......:) -- thanks again...
.
...................................CF
Ya know, that all depends, CF! My family and I experimented with 2 meters. I bought a popular repeater that's marketed to hams (it's actually 2 mobiles in a rack-mounted box, but...), then I had a friend give me a 2 meter duplexer (which had desense from scorch marks to the silver plating on the internal plungers and finger stock from being tuned under power), then I bought a new duplexer and had it factory tuned, and still had desense, then I changed antennas (and still had desense... maybe not enough isolation back into the repeater?). It was becoming an ordeal. So, all that was shelved and we went back to 440. Things were good - as long as we were within range of each other or the repeater. But we lost the car-to-car range we had on VHF. And, that still wasn't anywhere near what we had on 6. And, 440 is always in someone's spectrum cross-hairs.

That move to 6 represents an easy and inexpensive way to get range without a big investment in infrastructure. I mean, sure, the repeaters are there. The networks are mature now. It's not like 15 years ago when people were trying to link repeaters on US Robotics 56k dialup modems in some parts. But that dependence on infrastructure will not serve us well in a "bad day" scenario. 6 is really an untapped resource for that - and, since we're scannerheads, too - I'd be remiss in not saying VHF Low Band is a tremendous infrastructure agnostic resource for any kind of continuity of operations planning, whether that's for public safety or business. Might not be the first choice for every day, but it's the first choice (aside from NVIS... if we have an ionosphere to work with...) for a bad day.
 

SCPD

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Smiling :)
I think we are pretty much in agreement 902, and I've been enjoying the discourse, especially as it deals with low band vhf mobile.
Here where I work we have access to everything from HF Sideband, V/Uhf FM/DMR, trunked 800Mhz, even SatComm.... but once away from all the supporting intrastructure far out in the deserts, or up in the High Lonesome, we use simple low band 40 mhz FM for our field projects... 110watt Motorolas with those long, awkward stainless steel quarter wave whips. There is a lot of nothing-ness in the deserts and mountains of New Mexico, Arizona and Nevada where I run my projects and even though there are few corners of the lower 48 that don't have something Trunked into every gulch and mountain valley, I have had enuff experiences (bad) with setting up a test only to find it was a no-go because of a communications failure- usually due to a lightning strike on one of those microwave sites...
We have tried HF SSB in the past; NVIS is super, but except when we are working in the far Pacific- where it is used all the time, I had to give up on it domestically.... our Tech's can make anything talk-- but some of our scientists-------- can barely plug a coffee pot into a wall and get it to work. Like one of our engineers summed it up, "(Sideband radio) was like teaching the proverbial pig to dance-- first, it can't be done, and second it annoys the hell out of the pig (scientist)"............. we can get them to successfully dial up one of 6 possible 40 meg channels...;)..... and these frequencies do fantastically for separated sites out to +50 miles- mobile to mobile.
I think, like you said, the low band vhf's is a vast overlooked treasure trove of possibilities. Perhaps it, like so many things technological, just got bypassed as the state-of-the-arts moved to higher and higher frequencies and fancier and fancier modes.
All this got me musing on the subject.. and today I asked one of Tech's if he thought we could experiment with a low band repeater.....he, having a lot of experience with such-- and his thoughts about it?, a firm "No!'.. which then basically boiled down to his reluctance to deal with duplexer cavities and the extremes in temperatures on the repeater sites (+100 to -30F.)---- "Please don't ask me to set up one!" ........ I Didn't (lol) ... :)
'
..........................................CF
 
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KD8DVR

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I've made a dipole for my vx7r. It can be fun as an easy "I wanna play" type project.

Sent from my LG-D631 using Tapatalk
 

Token

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For the life of me I could never understand the philosophy of putting a repeater on low band VHF frequencies. Maybe in the 1950's or 60's they made some sense, when technology was still low banded-- but with all their limitations (ie; propagation, antenna size----) they make about as much sense as 75 metre repeaters today. Low band remotes, yes, but leave the repeats to the high band VHF and UHF's. If I am offending anyone, I would love to hear their good argument for 29 and/or 52 Mhz repeaters-- I can come up with none myself.

Because it is there, and it works, and why not? While nether band is great for HTs (although there are a few on 6M), they are fine for mobiles.

I don't see why NOT to put repeaters on 6 or 10 meters. It provides a change, something different, we have enough repeaters (well, can you ever really have enough?) on 2 meters and up, and they all act almost the same regardless of band, but 10 and 6 are different, and that can be interesting. When the band is open people using low power mobiles, or even hand helds, can catch some interesting DX, the repeater providing an extra 10+ dB of SNR over what the mobile could do. Yeah, I have done coast to coast with an HT on 6M, via a local repeater. When the band is not open the repeaters on 10 and 6 act much like higher band repeaters, but with a bit better fringe operation.

Even when the band is open the utilization on 10 M above 29.000 MHz is pretty sparse, so what does it hurt to give up 200 kHz of that to repeaters? And 6 meters is 4 MHz of bandwidth that I have never seen heavily occupied, even under the best of conditions a few solar cycles back. Sure, below 51.500 MHz can be busy when the band is open, as can 52.525 MHz and 52.540 MHz, but even when the band is wide open you seldom see much activity above 52.000 MHz...except a few repeaters.

I use 52.525 MHz near daily (for my commute it gets to my wife at home much better than any higher freq, and there are no repeaters that cover my full commute, and no cell coverage for much of the trip), and I use a repeater on the band pretty often also. In fact one 6 meter repeater provides coverage in areas no 2 M or 70 cm repeater can touch...despite the higher freq repeaters being on the same tower.

T!
 

prcguy

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A new 6m repeater just went up close to me on Catalina island off the coast of So Cal and 23mi not line of sight from my house. I can key it up full quieting with a 5w handheld with a lossy 3ft long antenna right on the hand held. That's pretty good performance considering the repeater antenna is only one single folded dipole and my antenna is sub quarter wavelength with a lossy broad band matching circuit.

There is a 2m repeater at the same location that works well but its got a 4-bay dipole array and a lot more gain.
prcguy


Because it is there, and it works, and why not? While nether band is great for HTs (although there are a few on 6M), they are fine for mobiles.

I don't see why NOT to put repeaters on 6 or 10 meters. It provides a change, something different, we have enough repeaters (well, can you ever really have enough?) on 2 meters and up, and they all act almost the same regardless of band, but 10 and 6 are different, and that can be interesting. When the band is open people using low power mobiles, or even hand helds, can catch some interesting DX, the repeater providing an extra 10+ dB of SNR over what the mobile could do. Yeah, I have done coast to coast with an HT on 6M, via a local repeater. When the band is not open the repeaters on 10 and 6 act much like higher band repeaters, but with a bit better fringe operation.

Even when the band is open the utilization on 10 M above 29.000 MHz is pretty sparse, so what does it hurt to give up 200 kHz of that to repeaters? And 6 meters is 4 MHz of bandwidth that I have never seen heavily occupied, even under the best of conditions a few solar cycles back. Sure, below 51.500 MHz can be busy when the band is open, as can 52.525 MHz and 52.540 MHz, but even when the band is wide open you seldom see much activity above 52.000 MHz...except a few repeaters.

I use 52.525 MHz near daily (for my commute it gets to my wife at home much better than any higher freq, and there are no repeaters that cover my full commute, and no cell coverage for much of the trip), and I use a repeater on the band pretty often also. In fact one 6 meter repeater provides coverage in areas no 2 M or 70 cm repeater can touch...despite the higher freq repeaters being on the same tower.

T!
 

SCPD

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Hey Token...I agree....while the practical, budget watching, effort-miserly little me says to the low band repeaters..."Why ??!!"
the Ham in me says-- "Why Not!?"
Heck, now you've all started me thinking, ....maybe we'll try out something simple in the way of a low band repeater... Maybe.......something *simple*........Maybe....Hmmmmm.........I know where there's a set of cavities sitting just looking for a mission..................................................................
.
You all aren't holding your breaths I hope....:) ! (lol !)

........................CF
 
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