Thanks, Patrick I've been considering "retiring" my TH-D7, and I think you just sold me on the new Kenwood! 73, Jim KQ6EA
On 12/06/2010 04:24 AM, Patrick STODDARD (WD9EWK/VA7EWK) wrote: > Hi! > > I wavered on whether I was going to get this radio straight away, after > the fiasco (related to FM satellite operation) the Alinco DJ-G7T was > last year. I didn't want to get bitten by a radio that was supposed to > be capable of full-duplex operation, but fall short like with the DJ-G7T. > After some thought, and after yesterday's hamfest, I drove over to the > local HRO store to see if they had any in stock. At mid-afternoon, HRO > still had 3 on the shelf at this store. I decided that, if the TH-D72 is > the true successor to the TH-D7 including the cross-band full-duplex > capability for FM voice satellite operation, I'd take the plunge. I > bought the radio and the only option they had for it in the store > (cigarette-lighter cable, compatible with several other Kenwood HTs > including the TH-F6A I purchased a few weeks ago). > > I charged the battery last night, and cleared some time this afternoon to > go out to my favorite city park to try it out. Not having used a Kenwood > HT on the satellites except for the TH-F6A as a receiver, I read through > the manual to make sure I had it set up for FM satellite work. I looked > at a few parameters I felt would be useful: > > 1. Transmit with VFO B, receive with VFO A. VFO A has better sensitivity > than VFO B, so why not go with that? There is no restriction on which VFO > can be the transmitter for this radio. > > 2. Audio balance. I set that all the way to VFO A, since I wasn't > interested in hearing VFO B. I could see with the S-meter if anyone else > was transmitting on the satellite uplink, and then rebalance the audio if > necessary to hear it. > > 3. Squelch. Open all the way on VFO A, tight on VFO B. > > 4. "DUP". This was a new one for me, not being familiar with the TH-D7 in > the past. Once I figured this out, turning it on for my transmit VFO (VFO > B), I was able to hear audio from VFO A whether or not I was transmitting > on VFO B. > > I had to get a plug adapter to use my normal audio cable/splitter setup > for an earpiece and my audio recorder with a Kenwood HT and its smaller > speaker jack. I already had one for my TH-F6A, and it worked fine with > the TH-D72A. I made sure tuning steps on both bands for both VFOs were > at the smallest step (5 kHz), and that I had VFO B set for high power > (5W). > > I started with the AO-27 pass at 2102 UTC. A very high pass here, with > maximum elevation of 80 degrees. I worked 7 stations in 7 minutes, and > received good reports on my audio through the satellite with the new > radio. The only issue I had in hearing the downlink wasn't due to the > radio - I had to move the antenna around as it passed over my head, and > there was a moment or two where the downlink audio was less than ideal. > I had to switch VFOs when tuning the receive VFO, something I don't have > to deal with on my IC-2820H mobile radio or when I use memory channels in > a non-full-duplex radio, but that was not a problem. > > The second pass I attempted with the TH-D72A was on AO-51 around 2322 > UTC. This was also a high pass, with maximum elevation of 63 degrees out > here. I had a little bit of difficulty hearing the satellite in the first > minute or so of the pass while transmitting, which could have been related > to how I was holding the antenna (Elk log periodic). I found during this > pass that I had to twist the antenna to clear up any receive issues while > transmitting. I think I might have heard the slightest desensing during a > couple of my transmissions, but that could have been related to how my > antenna was oriented toward the satellite. I logged 10 QSOs on the AO-51 > pass, which wasn't bad for all the activity on there. > > As I posted earlier and said on the air, the TH-D72A is the real deal as > a dual-band HT for full-duplex FM satellite operation. It does what the > DJ-G7T could not do, and I didn't even have to use the expanded manual on > the CD that came with the radio to get it set up for satellite work. I > also set it up to work on APRS, which took little time to do. I have not > tried it with a computer, to see if it will work as N8MH asked earlier. > Packet is actually something I was not very interested in for this radio - > FM satellites first, APRS next. The radio's GPS took only a few minutes > to pick up signals when I first activated it. > > I do not have test equipment to quantify how well the TH-D72A's receiver > is and how it compares to other radios. From playing with it last night > and today, I know the receiver is on par with the IC-2820H I usually run > on FM birds. Excluding transmitter power, the only thing the 2820 has > over the TH-D72A is its separate knobs for each VFO. It also compares > favorably with the sensitivity of my IC-T7H HT - the radio I've used on > satellites from outside Hara Arena in Dayton (my other radios' receivers > get swamped with intermod there, but not the IC-T7H). I will have to > test it in a high-RF area like that at Dayton, to see if intermod plays > havoc with the weak satellite downlinks. > > I'll work with this radio more, to get more familiar with it and possibly > work it into my demonstrations. I will eventually get around to hooking > it up to a computer, and seeing what I can do with packet and APRS. If > I'm not careful, I might even go as far as having an all-Kenwood HT > station for the OSCAR Straight Key Night in a few weeks (TH-D72A as CW > transmitter, TH-F6A as receiver). > > 73! > > > > > > > > Patrick WD9EWK/VA7EWK > http://www.wd9ewk.net/ > > > > _______________________________________________ > Sent via [email protected]. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
