VHF/UHF radio and antenna questions

[KY_Ham_64]

Got my 50ft of LMR type cable delivered today. Will try it out when I get home. We're expecting big storms tomorrow so it won't be up on the pole then.

I think I got a good deal it's BR400, a LMR 400 equivalent, $50 for 50ft, hope it's the real deal. The vendor is radio research online.

I already have 6ft of this cable, it's not real flexible. How much of a bend is tolerable with this type cable before you compromise its integrity?

LMR400 Type Coaxial Cable Assembly With PL259 Connectors 25 50 75 100 Feet BR400 | eBay

LMR400 type coax cable assembly with PL259 to PL259 (UHF Male) connectors. This cable is not as flexible as RG213 type coax cable with stranded center conductor. DC resistance inner conductor 1.39 Ohms/1000' 4.56/km.

www.ebay.com

 

[mmckenna]

Well, it's Browning. Browning/Tram were big American manufacturers several decades ago, but aren't anymore. The rights to the names were bought up by an American shell company and they've been reselling cheap Chinese products.

So, it's not true Times Microwave LMR-400. It's, as the e-bay listing says, "LMR400 type coax".
The question is: how closely did the manufacturer follow the specifications of the real stuff.

Good question.

If it was the Times Microwave LMR-400, the bend radius is 1 inch, but ideally you'd want to keep it a bit bigger than that long term. The risk is the center conductor can migrate out of the center and towards the shield.
With this being a different brand with unknown origin, I'd give it a lot of room.

Chances are, it's probably fine for what you are doing. Price was OK. Last time I bought a reel of the Times-Microwave stuff, I think I paid 79¢ a foot, but that didn't include the connectors. $1/foot with connectors installed is probably a good deal if the cable really is similar to true LMR-400.

 

[KY_Ham_64]

Well, it's Browning. Browning/Tram were big American manufacturers several decades ago, but aren't anymore. The rights to the names were bought up by an American shell company and they've been reselling cheap Chinese products.

So, it's not true Times Microwave LMR-400. It's, as the e-bay listing says, "LMR400 type coax".
The question is: how closely did the manufacturer follow the specifications of the real stuff.

Good question.

If it was the Times Microwave LMR-400, the bend radius is 1 inch, but ideally you'd want to keep it a bit bigger than that long term. The risk is the center conductor can migrate out of the center and towards the shield.
With this being a different brand with unknown origin, I'd give it a lot of room.

Chances are, it's probably fine for what you are doing. Price was OK. Last time I bought a reel of the Times-Microwave stuff, I think I paid 79¢ a foot, but that didn't include the connectors. $1/foot with connectors installed is probably a good deal if the cable really is similar to true LMR-400.

The cable specs on this RR page show about 0.7dB losses at 50ft on VHF, the range I'll be using most of the time. Not too bad IMO. UHF losses are about 1.3dB. Guess I'll see when I get everything hooked up and run thru my SWR meter.

LMR-400 Low Loss Coaxial Cable Assemblies, 50 ft.

LMR-400 Low Loss Coaxial Cable Assembly, 50 ft.

www.radioresearch.us

 

[mmckenna]

The cable specs on this RR page show about 0.7dB losses at 50ft on VHF, the range I'll be using most of the time. Not too bad IMO. UHF losses are about 1.3dB. Guess I'll see when I get everything hooked up and run thru my SWR meter.

LMR-400 Low Loss Coaxial Cable Assemblies, 50 ft.

LMR-400 Low Loss Coaxial Cable Assembly, 50 ft.

www.radioresearch.us

I'm sure it's fine for your application and the price wasn't bad. Enjoy it.

 

[KY_Ham_64]

Put the X200 on a 3ft tall pole that had been used for a satellite dish, which was removed years ago. Hooked up the new cable to it, ran the other end into my SWR meter and from there into the radio. SWR was dead on 1:1, virtually no reflected power, so very good there.

Made a few contacts with 25W power on the closest repeater (16 miles), they said my signal was strong with full quieting. Hit some other more distant repeaters, but no contacts.

So I'm encouraged by the new antenna and cable performance. Can only imagine how good it will be up on that 19ft mast.

 

[AK9R]

Good news, but be careful of repeater signal reports. What matters is how well the repeater is hearing you, not how well you or other users are hearing the repeater. Some folks will give you stellar signal reports through a repeater when they are, in fact, basing their report on the output of the repeater.

A better test would be to see how well you can communicate with those around you on simplex. That way, there's no repeater involved. Just a boy and his radio.

 

[KY_Ham_64]

Good news, but be careful of repeater signal reports. What matters is how well the repeater is hearing you, not how well you or other users are hearing the repeater. Some folks will give you stellar signal reports through a repeater when they are, in fact, basing their report on the output of the repeater.

A better test would be to see how well you can communicate with those around you on simplex. That way, there's no repeater involved. Just a boy and his radio.

You're right. But while he was hearing me on the closest repeater with no problems, his signal wasn't that great. Yes I could understand what he was saying, but there was quite a bit of noise. I don't really have an S meter on this radio, so I can't say what it was, but based on what I've read and seen on YouTube maybe an S5-7?

So yeah I probably need to see if we can do a simplex connection to really test things out. He seems to be on this repeater quite a bit so I'm sure he wouldn't mind.

Question about UHF, is the receiving distance shorter at these frequencies compared to VHF? I've yet to make a contact on UHF despite having quite a bit of power, and many repeaters to reach. I get replies from the repeaters. So maybe it's just that there's not that many folks that hang out on UHF?

 

[mmckenna]

Question about UHF, is the receiving distance shorter at these frequencies compared to VHF? I've yet to make a contact on UHF despite having quite a bit of power, and many repeaters to reach. I get replies from the repeaters. So maybe it's just that there's not that many folks that hang out on UHF?

70cm UHF or GMRS UHF?

70cm is pretty quite in most areas. Those that do use it tend to hang out on repeaters. I think in all my decades as a ham, I've only hear simplex on 70cm once.

GMRS? You'll find that most of the consumer radios default to some PL tone on them. It can be difficult to get a random simplex contact going.

UHF/VHF do behave differently. VHF is a bit more favorable in the hills. UHF is a bit more favorable in the cities. Range can vary a bit, but UHF antennas are smaller and require less ground plane, so it's easier to have a more efficient setup than on VHF, especially with hand held radios.

 

[KY_Ham_64]

70cm UHF or GMRS UHF?

70cm is pretty quite in most areas. Those that do use it tend to hang out on repeaters. I think in all my decades as a ham, I've only hear simplex on 70cm once.

GMRS? You'll find that most of the consumer radios default to some PL tone on them. It can be difficult to get a random simplex contact going.

UHF/VHF do behave differently. VHF is a bit more favorable in the hills. UHF is a bit more favorable in the cities. Range can vary a bit, but UHF antennas are smaller and require less ground plane, so it's easier to have a more efficient setup than on VHF, especially with hand held radios.

I'm talking just regular 70cm, not GMRS. I have some of the latter on HT's so me and my wife can use them.

So it seems that getting a dual band radio isn't really worth it. I do live in a hilly sparsely populated area, so VHF would make more sense. But if I do get in a more urban area UHF would be good to have.

 

[mmckenna]

So it seems that getting a dual band radio isn't really worth it. I do live in a hilly sparsely populated area, so VHF would make more sense. But if I do get in a more urban area UHF would be good to have.

Your milage may vary.

I've personally found that spending the extra money on a dual band radio wasn't a good investment for me.

I'd look at the available 70cm repeaters in your area. That would tell you if there is any interest. If there isn't, it's probable that there is very limited 70cm simplex use. 70 cm can bounce around in canyons pretty well, and it can be interesting. But for me, it wasn't worth the money. VHF is usually preferred by public safety in hilly terrain.

My own experience in my own area, in my own travels, with my own radios…..
2 meters is much more popular. If you are looking for simplex random contacts, you'll have better luck on 146.52 as opposed to 446.000.
It's pretty rare to find someone with -only- a 70cm radio. Usually they have dual band, or only 2 meters.
So you'll probably find the chances of doing simplex will be higher on the 2 meter band.

But the other thing I've learned:
Hams love to prove each other wrong. The best way to incite an absolute blind panic in the ham community is to make a statement that suggests a band/mode isn't used as much as others. Someone will get absolutely triggered and have to start posting about how we're all wrong and said band/mode is heavily used in their area and that we are absolute fools for not sinking our entire retirement savings into a bunch of radios that work on said bands/modes and that we are missing out on the "real" amateur radio experience.

So, you better run out right now and buy a 70 cm radio or you are going to upset the delicate feelings of some other ham.

 

[AK9R]

So it seems that getting a dual band radio isn't really worth it. I do live in a hilly sparsely populated area, so VHF would make more sense. But if I do get in a more urban area UHF would be good to have.

As I recall, you're in a rural area near Mt Sterling. I lived in Winchester for a while in the early 2000s and my recollection is that there just wasn't much activity on VHF/UHF amateur radio. Even in Lexington, VHF/UHF activity was not what I was used to in Indianapolis. In Lexington, repeaters were quiet except for a weekly net on one of them, but there was some activity on 2m simplex.

Is a dual-band radio worth it in your situation? Well, I'm not you. But to me, a dual-band radio is definitely worth it. True dual-band radios have two receivers so I can monitor two different frequencies simultaneously. I'm a railfan, so I'm very likely to have a local amateur radio repeater tuned in on "side" of the radio and a local railroad channel on the other "side".

 

[nokones]

"delicate feelings of some other hams" means more Sad HAMs, oh my.

 

[KY_Ham_64]

Your milage may vary.

I've personally found that spending the extra money on a dual band radio wasn't a good investment for me.

I'd look at the available 70cm repeaters in your area. That would tell you if there is any interest. If there isn't, it's probable that there is very limited 70cm simplex use. 70 cm can bounce around in canyons pretty well, and it can be interesting. But for me, it wasn't worth the money. VHF is usually preferred by public safety in hilly terrain.

My own experience in my own area, in my own travels, with my own radios…..
2 meters is much more popular. If you are looking for simplex random contacts, you'll have better luck on 146.52 as opposed to 446.000.
It's pretty rare to find someone with -only- a 70cm radio. Usually they have dual band, or only 2 meters.
So you'll probably find the chances of doing simplex will be higher on the 2 meter band.

But the other thing I've learned:
Hams love to prove each other wrong. The best way to incite an absolute blind panic in the ham community is to make a statement that suggests a band/mode isn't used as much as others. Someone will get absolutely triggered and have to start posting about how we're all wrong and said band/mode is heavily used in their area and that we are absolute fools for not sinking our entire retirement savings into a bunch of radios that work on said bands/modes and that we are missing out on the "real" amateur radio experience.

So, you better run out right now and buy a 70 cm radio or you are going to upset the delicate feelings of some other ham.

There's plenty of 70cm repeaters around here, just about as there are 2m. I'm not regretting getting a dual band radio, it has dual receive capability on it, and has some nice features. It's nice to know I have UHF capability on it when I need it.

This FTM150 has this "Super DX" feature on it that's a fancy type of squelch, it's supposed to enhance weak signals, but I've noticed it kind of squashes it if it's really not that strong. Kind of opposite of what it's supposed to do.

It also has a PMG (Primary Memory Group) feature that allows you to have like a 5 channel continuous scan which allows to you monitor all 5 channels at once.

Other than that it's not a real fancy radio, but it seems to be pretty solid in the short time I've used it.

 

[KY_Ham_64]

A question about the install of the X200 on the 19ft pole. I'm guessing I'll need to do some heavy duty weather proofing. This antenna has a metallic joint where the two elements are joined. It's supposed to be water proof, but should this joint be taped to make sure? I'm also guessing the area where the coax connects to the bottom of the antenna will need to be protected as well. Any suggestions on what type of tape? Is that Coax Seal pretty good for this application?

 

[mmckenna]

There's plenty of 70cm repeaters around here, just about as there are 2m. I'm not regretting getting a dual band radio, it has dual receive capability on it, and has some nice features. It's nice to know I have UHF capability on it when I need it.

Then, if you've got the capability to work simplex on 70cm, give it a try. You may have a different experience than I've had.

A question about the install of the X200 on the 19ft pole. I'm guessing I'll need to do some heavy duty weather proofing. This antenna has a metallic joint where the two elements are joined. It's supposed to be water proof, but should this joint be taped to make sure? I'm also guessing the area where the coax connects to the bottom of the antenna will need to be protected as well. Any suggestions on what type of tape? Is that Coax Seal pretty good for this application?

These kits are the way most professionals do it. It's proven to work. I've disassembled connections there were sealed this way back in the early 1990's, and everything was clean, shiny and dry.

Commscope 221213 Universal Weatherproofing Kit for Coaxial Cable Connectors

Manufacturer: Commscope; Universal Weatherproofing Kit; Weatherproofing tape kits flawlessly seals the junction between two connectors. It not only protects

theantennafarm.com

You can sometimes find those kits on e-Bay for less money.

As for installation, this is the method used in the industry and it's been proven to work:

https://www.telewave.com/wp-content/uploads/2016/12/TWDS-0502.pdf

 

[K6GBW]

For the antenna you are describing, I’d just use the brand named tape called Coax Seal. You can get it at any amateur radio supply place. It’s amalgamating tape and after a few weeks it’s really and truly sealed. The trick is you need to wrap it correctly. Start below the connector on the actual coax and wrap it going up. This overlaps so that water running down slides off like with roof tiles. Pull the tape so that it is tight. I mean really stretch it and work slowly up to the top, making sure to wrap the threads on the connector. Once this is done, repeat the process with vinyl tape, something like Scott 33 or similar. Once that’s all done reassemble the mounting tube. There is no need to seal the tube unless you want to keep bugs and spiders out. For that I usually use a green scrubber pad and cut it into smaller chunks and push it up inside the tube. This allows air to still move and helps keep condensation down. Sealing Comet and Diamond antennas this way I’ve never ever had a leak.

 

[KY_Ham_64]

For the antenna you are describing, I’d just use the brand named tape called Coax Seal. You can get it at any amateur radio supply place. It’s amalgamating tape and after a few weeks it’s really and truly sealed. The trick is you need to wrap it correctly. Start below the connector on the actual coax and wrap it going up. This overlaps so that water running down slides off like with roof tiles. Pull the tape so that it is tight. I mean really stretch it and work slowly up to the top, making sure to wrap the threads on the connector. Once this is done, repeat the process with vinyl tape, something like Scott 33 or similar. Once that’s all done reassemble the mounting tube. There is no need to seal the tube unless you want to keep bugs and spiders out. For that I usually use a green scrubber pad and cut it into smaller chunks and push it up inside the tube. This allows air to still move and helps keep condensation down. Sealing Comet and Diamond antennas this way I’ve never ever had a leak.

Thanks for the suggestions. I can get some Temflex 2155 and Scotch 33+ at Lowe's tomorrow. Is Temflex as good as Coax Seal?

Will probably do this in a few days, want to see if being up about 20ft AGL will make a difference. It'll be higher than the roof by about 6ft so the house won't be an issue. We have a hill to the west behind us that goes about 150ft up. But we're on a hillside with hills a half mile away to the east and the valley opens up somewhat to NE to SW.

I can't hit the repeater that's about 20 miles west because of the hill so I hope the extra elevation will help. The antenna is 8ft long but I'm not sure what its radiation pattern is.

 

[K6GBW]

The Temflex should work fine. With VHF/UHF antennas there is a subtle compulsion for more gain, but gain isn’t always a good thing depending on the relative elevation of the station/repeater your’e trying to contact. I’ve found moderate antenna gain helpful but height is functionally more important. So I always suggest getting your antenna as high as you reasonably can. A quarter wave antenna at 30 feet is going get you more than a high gain antenna at 10 feet. All that said, don’t go crazy. I’ve seen some guys get insanely reckless in trying to put up cobbled together masts at heights that aren’t really prudent or safe. Also, for VHF and especially UHF the coax really does matter. I’d look to something like LMR400 or similar as a minimum.

 

[KY_Ham_64]

The Temflex should work fine. With VHF/UHF antennas there is a subtle compulsion for more gain, but gain isn’t always a good thing depending on the relative elevation of the station/repeater your’e trying to contact. I’ve found moderate antenna gain helpful but height is functionally more important. So I always suggest getting your antenna as high as you reasonably can. A quarter wave antenna at 30 feet is going get you more than a high gain antenna at 10 feet. All that said, don’t go crazy. I’ve seen some guys get insanely reckless in trying to put up cobbled together masts at heights that aren’t really prudent or safe. Also, for VHF and especially UHF the coax really does matter. I’d look to something like LMR400 or similar as a minimum.

Thanks, I'll pick up the taping material today.

I didn't get the highest gain antenna (GP-9), I read somewhere that the shorter antennas might have a more elevated radiation pattern, which would benefit me better in my location.

My antenna mast is a older metal pole that seems to be in good shape, I'm not going to add an extension to it.

I got my cable in Thursday and tried it out with my X200 mounted on an old 3ft satellite pole in the front yard. The SWR on both bands were 1:1, with virtually no reflected power. It's 50ft of LMR400 type cable.

LMR-400 Low Loss Coaxial Cable Assemblies, 50 ft.

LMR-400 Low Loss Coaxial Cable Assembly, 50 ft.

www.radioresearch.us

 

[K6GBW]

To imagine gain think of it like a ballon sitting on a table. It’s pretty much round. Now push it down against the table with your hand and you see that it spreads out to the sides. That’s pretty much what gain does. Sometime that’s helpful, like when talking simplex across a flat desert. Sometimes it’s not helpful, like when trying to get into a repeater that is significantly higher than you are. I’ve found that something in the middle is usually the most practical.

Height on the other hand gets your antenna above the ground clutter and a better view of the horizon. VHF and UHF is line of sight, so seeing further is very helpful in almost all cases.