marcspaz Posted February 10, 2020 Report Posted February 10, 2020 Today, I put together a new portable repeater antenna setup together. I do a lot of work with Amateur Radio Emergency Service. Often, we need a repeater setup so our people can run around with HT's and still be able to communicate direct with everyone. The antenna is setup for 2m, 70cm and GMRS. In all services, the SWR is 1.2:1 or better. It's sitting on top of a fiberglass mast. The total height is 47 feet from the ground to the top of the antenna. The bottom of the antenna is 40' from the ground. My son Nick is next to it to use as a reference. I tested it out on 2m. Full quiet to another station 40 miles away, with only 5 watts. I'm pretty happy with that. On 70cm and GMRS, I was full quiet to a repeater 22 miles away with just 2 watts. I am pretty happy with this setup. I am going to be doing a training drill on March 28. We'll see how it goes. http://fiveguysracing.com/marc/HAM-GMRS/Pot_2m-440_Repeater_Antenna_2.jpg http://fiveguysracing.com/marc/HAM-GMRS/Pot_2m-440_Repeater_Antenna_3.jpg Soladaddy, coryb27, kipandlee and 1 other 4 Quote
gortex2 Posted February 10, 2020 Report Posted February 10, 2020 Nice setup but watch the Tripod you have. I tried similar setup for our SAR team in the past and it didn't last well in some wind even with guy wires up. We since switched to a military style mast kit we found here - https://www.ebay.com/itm/ANTENNA-TRIPOD-29FT-ALUMINUM-PORTABLE-TOWER-MAST-KIT-NEW/361384099911 It is night and day better and faster to set up that what we had before. It cost a bit more but in the end it was worth it. The selling point of the tripod is the custom "tripod" adapter he ships with it. Here it was last summer in the national park. This was hooked up to a mixed mode Quantar for an event we handle comms for. marcspaz and kipandlee 2 Quote
marcspaz Posted February 10, 2020 Author Report Posted February 10, 2020 I've seen this before. I like them, but have had trouble finding one at a reasonable price. The one I have right now is supposed to be bolted/screwed down to a building's roof. So, the footprint is very small. It's not ideal for tall setups. Nice setup but watch the Tripod you have. I tried similar setup for our SAR team in the past and it didn't last well in some wind even with guy wires up. We since switched to a military style mast kit we found here - https://www.ebay.com/itm/ANTENNA-TRIPOD-29FT-ALUMINUM-PORTABLE-TOWER-MAST-KIT-NEW/361384099911 It is night and day better and faster to set up that what we had before. It cost a bit more but in the end it was worth it. The selling point of the tripod is the custom "tripod" adapter he ships with it. Here it was last summer in the national park. This was hooked up to a mixed mode Quantar for an event we handle comms for. Quote
gortex2 Posted February 11, 2020 Report Posted February 11, 2020 Yup he is pretty firm on his price. We were able to get a donation to help out and get it. May be worth grabbing a 4'x4' sheet of 3//4 plywood to throw on the ground first and screw or bolt it to it. Then throw some blocks or something heavy on it ? I had spikes pounded in the ground on all three when ours blew over. They were about 16" long but the ground was mostly sand and didn't help much. kipandlee 1 Quote
marcspaz Posted February 11, 2020 Author Report Posted February 11, 2020 Yup he is pretty firm on his price. We were able to get a donation to help out and get it. That's a good idea. It is volunteer work and it does get expensive. I may go that route if needed. May be worth grabbing a 4'x4' sheet of 3//4 plywood to throw on the ground first and screw or bolt it to it. Then throw some blocks or something heavy on it ? I had spikes pounded in the ground on all three when ours blew over. They were about 16" long but the ground was mostly sand and didn't help much. I was going to use the spikes to stop sliding side to side, but I have some notched 10 lb weights I was going to drop on each foot, to help prevent tipping. The board idea sounds good, but I will lose the ability to easily transport and setup since I am using an SUV. If I had a pickup, I would just toss it in the back. Quote
n4gix Posted February 11, 2020 Report Posted February 11, 2020 I have two of the fiberglass tent pole 32' sets that I use to support a G5RV Jr (52' long) dipole here at my home antenna farm. Two of them split on the female end so I had to cut them just above the splits and I added some stainless steel radiator hose clamps to prevent the other poles from splitting. For field use, I have two fiberglass pushup masts (48') with lever action compression locks, and two of the giant (6') MFJ tripods. I hang a full-sized G5RV between the masts with three sets of guys on each of them. Marc, you ain't kidding that it can get expensive real fast! The field equipment set me back nearly $700... marcspaz 1 Quote
marcspaz Posted February 11, 2020 Author Report Posted February 11, 2020 I was thinking about getting one of the tripods with a 8 foot base and 5 feet high... but $200 vs the $25 for the 3 footer I have. Man. Quote
berkinet Posted February 12, 2020 Report Posted February 12, 2020 How about a DIY base using something like this http://ham-radio-antenna.net/photos/ANTENNA_RADIO_TOWER_ALUMINUM_ORANGE_TRIPOD_FOR_USE_WITH_MILITARY_48_MAST_POLE_02_gfo.jpg and some pipe or conduit. Take a look at this site or this site for a number of options. marcspaz 1 Quote
marcspaz Posted February 12, 2020 Author Report Posted February 12, 2020 I thought about that, too. One of the biggest things stopping me is there is no information on how big the center hole is. I need something that accommodates a 2" mast base. I can always reach out to the sellers. Just haven't yet. Quote
berkinet Posted February 12, 2020 Report Posted February 12, 2020 It appears the ID of the vertical mast hole is 1.8". So, it won't work with your 2" OD pipe. OTOH, you can get 48' of fiberglass mast (12 x 4') for around $90 that would work quite well with the base. Or, you could make a base section of the mast with a smaller sized pipe and an adapter to 2". marcspaz 1 Quote
axorlov Posted February 12, 2020 Report Posted February 12, 2020 The antenna is setup for 2m, 70cm and GMRS. In all services, the SWR is 1.2:1 or better. It's sitting on top of a fiberglass mast. What antenna is that? Quote
marcspaz Posted February 12, 2020 Author Report Posted February 12, 2020 What antenna is that? Diamond X200a. Quote
n4gix Posted February 16, 2020 Report Posted February 16, 2020 The fiberglass and aluminum poles are 1.75" O.D. so the I.D. of 1.8" for the tripod makes sense... gortex2 1 Quote
n4gix Posted February 16, 2020 Report Posted February 16, 2020 I was thinking about getting one of the tripods with a 8 foot base and 5 feet high... but $200 vs the $25 for the 3 footer I have. Man.On reflection, I should have bought the aluminum tripod base and six aluminum poles instead of the very expensive MFJ tripods. It would have been far more portable, weighed a LOT less, and been a heck of a lot cheaper! Ah well, hindsight is only depressing... marcspaz 1 Quote
gortex2 Posted February 17, 2020 Report Posted February 17, 2020 How about a DIY base using something like this http://ham-radio-antenna.net/photos/ANTENNA_RADIO_TOWER_ALUMINUM_ORANGE_TRIPOD_FOR_USE_WITH_MILITARY_48_MAST_POLE_02_gfo.jpg and some pipe or conduit. Take a look at this site or this site for a number of options. Thats the same guy that we got the entire kit from. I actually looked to just get the tripod then buy the tubes ouself. After talking to him about our idea it was apparent I could save some coin, or just buy a bag that has everything needed. He actually cuts all the aluminum poles so they slide thru the tripod and finishes the ends. Yes you could use poles with the ring on them but its slick as slick to just keep adding poles to the bottom and push it up. All his stuff comes in a bag that can be carried by one person up a mountain and setup. Quote
Elkhunter521 Posted February 18, 2020 Report Posted February 18, 2020 Hi, Im using 2" pvc pipe mounted on a pivot mount on my hunting trailer (16 x 7 ) enclosed cargo trailer. This pipe is 20 ft long. A 10 ft piece of 11/2 in.pipe extends this mast to 30 ft above ground. One of these for a gmrs repeater and one for CB. On opposite corners of the trailer. marcspaz 1 Quote
Soladaddy Posted April 25, 2020 Report Posted April 25, 2020 Diamond X200a.Wait, what? the X200a tunes up on GMRS? I'm move my coax right now. marcspaz 1 Quote
Soladaddy Posted April 28, 2020 Report Posted April 28, 2020 Well its sure does. I have 1.2:1 SWR on 462 and 467. marcspaz 1 Quote
marcspaz Posted April 28, 2020 Author Report Posted April 28, 2020 Well its sure does. I have 1.2:1 SWR on 462 and 467.Good deal... it's a heck of a performer. You're going to like the coverage you get out of it. Quote
kidphc Posted May 3, 2020 Report Posted May 3, 2020 Good deal... it's a heck of a performer. You're going to like the coverage you get out of it.Wonder if the x50a can do the same with GMRS.... would lead to a lot less crowding in the attic if I didn't have to put another vertical up there. Quote
marcspaz Posted May 3, 2020 Author Report Posted May 3, 2020 Wonder if the x50a can do the same with GMRS.... would lead to a lot less crowding in the attic if I didn't have to put another vertical up there. I have an x50a on the roof. I'll put the analyzer on it and let you know. Quote
marcspaz Posted May 3, 2020 Author Report Posted May 3, 2020 Okay... here are the X50a readings. They are pretty good considering the antenna was designed as an amateur radio repeater antenna. In the 462 range. http://fiveguysracing.com/marc/HAM-GMRS/x50a_on_GMRS/x50a_GMRS_Simplex_SWR.jpg In the 467 range. http://fiveguysracing.com/marc/HAM-GMRS/x50a_on_GMRS/x50a_GMRS_Repeater_SWR.jpg Elkhunter521 and kidphc 2 Quote
Elkhunter521 Posted May 3, 2020 Report Posted May 3, 2020 Hmm Marc, does your house look like a porcupine? Just asking. marcspaz and berkinet 2 Quote
kidphc Posted May 3, 2020 Report Posted May 3, 2020 Hmm Marc, does your house look like a porcupine? Just asking.Still choosing gear. But yes the attic looks like it will be a nest of pokey metal and wire. The odd shape doesn't allow for a 40m fan dipole, does fit a 20m with easy. I have enough space to get an x300 in there with height to spare, but due to the radials and trying to get a dipole in also I am leaning heavily towards the x50a, the dipole won't come as close to touching. Even then for gmrs I would probably put up a x30a on the other end. Currently, the thought is the fan dipole, x50a for hf and uhf. A switch with a set of halos for 2m ssb. But as usual your information gives me info that I couldn't find anywhere else. Sent from my SM-G975U using Tapatalk marcspaz 1 Quote
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