Begin date: 2018-12-22. Status: Current
Radio: Farren’s Yaesu FT-8900R in bi-directional cross-band repeat
Power: Ryan’s Astron 12A
Coax: The entire length as supplied by Mike — nearly half of it is in a coil – how does that affect things?
Antenna: Mike’s Tram Discone 1411 without the two lower stingers (yet)
Antenna height: Approx. 45′
Frequencies: 146.460, 446.025 simplex, no tones
RF Power: High on both bands after first two tests
Reports:
01: 2018-12-23 Mike: UHF, Ryan: VHF
Mike: Ryan was on his way to Clifton this evening so he and I did a Fusion Test through the RB X Band repeater…didn’t work. We got the noise but nothing decoded. The good news is that were were able to do FM almost all the way to Clay Center. Ryan lost the signal past the Bayer Quarry at the intersection of Brougton, Co 396, and Sunflower Road. Ryan’s configuration was a Yaesu FTM-400XDR, high power, with a Browning BR-180 antenna mounted in the roof of a Yukon.
02: 2018-12-24 Mike: UHF, Ryan: VHF
Mike: Ryan and I tested again as he was traveling…this time to the south and west. With the exception of a couple of bad spots, we were pretty good as far as Grandview Plaza right around exit 300 on I-70, it came back in another mile but then it was gone for good. That was pretty impressive, from Grandview to the RB site covers a lot of territory with a lot of high ground in between. But when the signal started to go it went real fast! Ryans configuration was a Kenwood TM-D710g, high power, with a Larsen NMO2/70B antenna on a lip mount on a back hatch Ford Escape.
At this point I adjusted the squelch on the 8900 to be much tighter as it was way too open. I also switched the UHF band from Mid to High power.
How much further would Ryan have gotten with the new squelch setting???
03: 2018-12-27 Mike: UHF, Farren: VHF
Farren: I talked to Mike all the way from the RB-TTL site to my house! While parked in my usual spot where I can cross-band into the MAARS repeater we were able to talk but there was some static. It was raining. Mike said my audio was “garbled” and I’m suspecting the rain doing something strange with the antenna.
04: 2018-12-29 Mike: UHF, Farren: VHF
Farren: Called Mike as soon as I topped the hill north of my house and got a “solid” report. We talked all the way to the hill south of Blue Rapids, even through the low spots but there was more static in the low spots. Mike didn’t hear me while I was in Blue Rapids but when I crossed the Blue River bridge east of town he said it was perfect copy. We were able to talk until Pheasant road. When I parked at my church (The Crossing) in Marysville, I called Mike. He reported that he could hear me clearly but I was barely able to understand him through the noise. When I was transmitting on VHF my UHF side didn’t even open the squelch. But, when I transmitted on the UHF side I could hear myself on the VHF side almost better than I was hearing Mike, which doesn’t make sense. Mike reported that the “garbled” audio was gone completely. We went from rain to below freezing, so if any water did get in the antenna, it’s probably frozen in there. Not sure water can explain the garbled audio. Farren’s configuration was a Yaesu FT-8900R and a mag-mounted dual-band Larson (I think)
05: 2018-12-29 Mike: UHF, Farren: VHF
Farren: On a family trip to White City I talked to mike pretty much the entire time from the Dillons East parking lot in Manhattan to Dwight. On the way home I took Hwy. 77 and talked from Junction City to Riley. Didn’t need to keep the test up as we’d already proven it works from Riley to my QTH. My configuration was a Yaesu FT-8900R and a cheap mag-mounted Tram antenna on a Chevy Express van.
Findings:
Mike, Ryan, and myself are amazed at how well this configuration works! The discone antenna has no gain and isn’t really intended for transmitting. While I don’t intend to leave a cross-band repeater operating full-time at the site, I do intend to test it with better antennas before moving on. Configuration #002 will be the same radio with an antenna that has modest gain. Config #003 might be the same radio with an antenna that has pretty high gain.
Notes:
We didn’t install the two lower stingers on the discone antenna because the docs led us to believe they were for the 11 meter band (CB) and we didn’t need that. But, once it was up on the tower an antenna analyzer revealed that the SWR at 10 and 6 meters was way to high even though Tram claims the discone will transmit on 10 and 6. A simplex test was tried on 6 meters between the RB-TTL site and Mike’s hilltop site and we were able to hear each other, but the signal was poor. I want to install those extra pieces on the antenna and try 6 meters again. If it works, I’ll select a 2 meter and a 6 meter frequency and do some cross-band repeater tests on those bands. If 10 meters works, I’m willing to do a cross band repeater on 10 meters as well, but I don’t have any other 10 meter equipment to test it with. (I have radios but no antennas.)
