tweiss3

Intent is to put up a repeater on 22 462/7.725 I'd like to setup a winlink gateway on VHF, but if needed I can figure that out later. This antenna is loved away from my other antennas, and is for services only, not normal use (Winlink, iGate & Repeater). My only must right now is the repeater.

I had originally planed to use an X300NA antenna to put up a repeater AND packet services for VHF ham. Today, I finally got around to unboxing the X300 and assembled. I clamped it to a tripod mount 5' above the ground in the middle of my driveway to check how it swept with the VNA. I also have an antenna that came with the repeater, that I think is a Laird Technologies FG4603 based on the size, color and shape. The specs between the two are below: X300 - 10' tall, 9.0db gain on UHF, 5/8 wave five element SWR: 462.68MHz - 2.525:1, 467.62MHz - 3.125:1, 449.67MHz - 1.461:1, 438.36MHz - 1.237:1 Laird - 3.66' tall, 5.0db gain SWR: 462.68MHz - 1.730:1, 462.30MHz - 1.698:1, 467.62MHz - 2.150:1 With the above, I have 22.8W leaving the duplexer, and with the mixture of fittings and coaxial, my coax loss is 0.559db. Using an SWR power forward calculator, and a EIRP power calculator I calculated the following: X300: 19.1 W forward power gives 53.40dB EIRP Laird: 21.28 W forward power gives 47.87dB EIRP Leaving everything the same, mounting height, coax, everything, and knowing here is a 6.34' top of antenna height advantage and 5.53dB EIRP advantage for the X300 with higher SWR over the other antenna, which one would you choose and why?

I signed up for the announcement that comes out in 10 days. Thanks @gman1971

I do have a go-kit radio that I use for hiking and doing parks on the air (6M,2M & 440 while in motion), but I also have EFHW in the bag, one for 40/20 only, and one that will do 10-80. For NVIS (which will get you closer contacts) anywhere around 10' above ground will work, but should be less than 30' in the air. That being said, I have worked Utah, Spain & England on 5W with a vertical on the car roof. The Elecraft are nice, but they are a bit pricy for a bag radio. I know quite a few guys that use them, but they are real points guys doing QPR on CW only. Depending on how you are planning on using it outside of emmcom, The 705 or FT818 will both be great. Both come with their own internal batteries, and can work with an external battery or power source. 705 will go up to 10W on external power, 818 only has 6W. 705 will require you get your own antenna for even 2m use, where the 818 can be used out of the box on 6m/2m/70cm with the included antenna. I have an 817 with a handful of accessories, and for what I paid for it as a used package, I have zero complaints, but if I were to buy another low power HF radio, it would be the 705. I still recommend it is a wonderful radio.

Well, it will do two good things. 1) There may be many more 7550e's on the used market soon 2) Maybe they improved things, like the antenna connector, or added mobile docking for the portables like the APX, I'd dump my current car radio in a second.

As does the XPR series radios for DMR. It's also why the Kenwood NX radios can support all 3 with just key changes.

Correct, P25P2 requires trunking/data channel to synchronize, so simplex flips back to P1 at 12.5kHz. The NXDN sound darn good on VHF, especially since my district has the lowest density due to being interwoven in the national parks system, our footprint is huge. I did find another school system that is low power, 4 site, 5 frequency DMR, but uses only 2 talkgroups (busses and facility/maintenance). They sounded good too, but their footprint is tiny and odd shaped (hence the number of sites. The real problem is there isn't any good current commercial equipment that the FCC has given Part 95 approval for. I'd love to see a current lineup get the stamp. Sooner or later, the EOL stuff is going to be boat anchors.

Yea, my VHF radio at home doesn't like my 1W APRS beacon that is 28' away from the base station antenna (144.39MHz to 147.27MHz). Though, looking at the sites for some local P25 P2 systems, they have frequencies as close as 0.275MHz, however, appropriate TX combiners and filters/cavities it wouldn't be an issue at all. I read somewhere that P25P2 was supposed to be FDMA (true 6.25 individual channels), but ended up TDMA, which is still ok since it is a 6.25 equivalent. I believe NXDN is the only true FDMA 6.25 mode available, and works well for the railroads, but it's not common on the public safety side (my school district uses it on VHF for the busses). As far as TETRA having 4 paths on one frequency, it does, but it is also TDMA in a 25k frequency, so basically 2 DMR stacked next to each other in 1 frequency. Long and short of it, I don't think DMR as we know it is going away. If they stopped acknowledging it as a 6.25 equivalent, then they would have to shut down P25 as well, and that won't happen.

This. I used a hammer the first time, was too much effort. Looking to drive another one soon, so I bought a hammer drill (keep saying I need one for various projects), I'm not doing one by hand again.

Good deal. Enjoy it, thanks for the pictures.

I would suggest you contact Oklahoma State Department of Homeland Security, which is who those interop frequencies are licensed to. It should also be noted, you likely won't get anyone on those frequencies. Looking at the license, the emissions designator is for P25, and considering the state has gone to P25 for OMACS there is likely not a single soul that will be listening to analog NFM to even pick up your call for help.

True, though how many analog repeaters are dead silent day in and day out. The point of digital in my opinion is to have options to reach further than the local RF footprint. I often have a good 5-10 minute qso from people in Dayton, Columbus, Cincinnati or even Toledo, all of which wouldn't ever be in range (with the exception of 1 repeater than manages to reach Canada and WV on a good propagation day). My real point is poor internet connections kill the DMR exprience, and lets be honest, the local use (RF to RF) is non existent. Look at this repeaters last used: And it's coverage is pretty massive. It's also been offline 95% of the time due to internet connection issues.

I would agree, the property setup stuff sounds great. Even further, a Moto or Hunters DMR repeater is hard to setup badly out of the box. We have a handful of the multimode repeater that sound good, but the technical team that maintains these those are really good and have the proper equipment. The biggest problem with DMR repeaters appears to be maintaining a good reliable internet connection. The Anytone sounds like junk no matter what, but it's loud, which is what many people like. Sound quality is exceptional on the XPR and SL radios, even on a hotspot. I even bought an SL7550 just for at home hotspot use, and it's always on the Ohio talkgroups 247. My CS800Ds do sound good, not as good as the Motos but much better than the trash Anytone.

I do it all the time. And not just by the bumper sticker, I do it via APRS as well, and I can call them out via call sign directly then, as I also have a distance between me and them too.

Well since there are so many limitations on what is not permitted on GMRS, I am guessing the only use for fixed stations in GMRS would be RF Links between repeater. Essentially use another repeater on the same site at 15 watts max on a different pair with a Yagi pointed at the other repeater site, creating a wide area repeater network without IP or any other infrastructure.

eCFR Title 47, Chapter I, Subchapter D, 95.303: Definitions "Fixed station. A station at a fixed location that directly communicates with other fixed stations only."

Is this simplex or via repeater? What does it sound like, just an open microphone, or is it a heterodyne sound like a perfect double between two stations? Could it be a station on a close frequency that may be overmodulated?

I have the Larsen NMO2/70sh with the spring base, it's commercial partner is the NMO150/450/758 (is also on the roof for my scanner) which would be the one tuned better for GMRS. Both get wacked off the parking deck at the hospital often, and even get beat up by the car wash without any issues.

That depends entirely on antenna height, and I would guess it is 250'+ in the air. Typically a home station is 50' or less, and short of going higher, I personally think it's better to take out losses that aren't necessary to every day operations.

If it was me, I'd leave it out. I was tuning up my repeater this weekend, verifying operation/programming/power/alignment before I move on to getting it on the air, and the little 2' N to PL259 jumper and one PL259 to N cable was worth 0.5db, add in the 0.3 for the meter, and that is on its way to significant loss.

I do not either. I do check occasionally, but I don't see it necessary. I'm assuming you are talking the SW102, which does have 0.3db insertion loss, plus adapters/connectors, so leaving it inline isn't "free", but it's not that much loss. Up to you. Do you have your cables terminated directly in N connectors, or are you using adapters?

@liahju What makes you think it needs adjustment? I'm assuming you have the tools/software to program it, correct? I guess, what are the symptoms you are having? Or is it more/less you think it might need adjustment? pull the duplexer cable off the transmit side and put a power meter on it. Verify frequency accuracy and power, it may not need anything. There is a great resource called Repeater Builder, and they have a whole section on that series of Motorola radios/repeaters: https://www.repeater-builder.com/motorola/r1225/r1225-overview.html

This is different, as its still the same "service".

Linear in wavelength, not linear in effect on the antenna SWR, especially many mobile antennas that have coils/capacitance in the bases.

The term "backup" has many stages, and isn't quite limited to just one method. I have enough batteries for my primary to last about a week, I have a small fleet of radios that could last about a week with limited usage, and that's just the handhelds. I also have the vehicular radios, then there are options for HF radio as well.