ATGP 2013 - Clingmans Dome - 22 July 2013

Well, just got in from Clingman's Dome, and we definitely had a "weather event" at Clingman's Dome. Around 2:15PM (EDT), we got hit with thunder, lightning, and a downpour that didn't show any signs of letting up. I barely got the antenna on the push-up mast down before the downpour started and got a good soaking anyway.

Tried to operate after that with a vertical on the car roof and could still work Roan Mtn. and Lookout Mtn. on voice, and Roan Mtn. on APRS.

We never received any packets from Springer Mtn. (I understand that operator diverted to Ft. Mountain due to heavy TS activity in the Springer area), nor could we establish voice contact.

An interesting experiment, nonetheless, and I can see some things I'll do differently next year if I get a chance to participate.

Larry J. Ford KG4GPJ

JMG:

I just posted the log file from the Clingman's Dome monitoring station (TH-D7 with mag-mount). It covers the period from 1200-1415. We were actually on the air by 1100.

The main station was Larry's TM-D700 using a vertical omni on an 18' mast. We had good voice contact with ROAN using 10W on the main station.

We were hearing packets from 3, 4, & 5 the entire time we were operational.

Never heard Springer directly but received a packet from Springer via Lookout.

Received a packet from Camelback near the end but I think the hop count was off. Received it from Roan with a path of HOP7-2 but was expecting to see HOP7-1.

We never saw anything from 6, 7, or 8.

Larry Ford:

I'm sure the folks on the peaks with high RF environments need filters, but that's not the case on Clingman's Dome, which is high enough (6600 feet MSL+-) and isolated enough (in the middle of the Great Smoky Mountains National Park), there's no other RF up there - no electricity either!

We had good comms on UHF to Roan Mtn. (89 miles) and Lookout Mtn (80+ miles). Both Roan and Lookout could copy our station on UHF on 10 watts (dropped power down on UHF to conserve battery capacity).

However, as reported before, we never heard a peep out of Springer (which supposedly diverted to Fort Mountain, GA, due to TS in and around Springer) on APRS or UHF. However, the alternate station on Lookout Mtn. did report at one time seeing a packet TX and may have had a brief UHF comm as well.

Lookout Mtn. reported that Springer/Fort Mountain was using a handheld. Don't know what kind of antenna he was using, or what his actual power output was, but for the leg between Springer and Clingman's Dome, I would suggest that 5 watts won't do the job unless conditions are near perfect and a good gain antenna is used.

Larry J. Ford KG4GPJ Clingman-2

P.S. regarding ...

Zach, Good job at Comer's Rock. I was at Clingman's Dome and your station was one of the 3 we were receiving early and continuously.

With regard to logging, one bad thing about the D700 is that when you put it into APRS mode you no longer receive the monitor packets that you do when in packet mode. You would have to operate in packet mode with an APRS client on your laptop, or manually beacon from a terminal program.

What I was thinking of doing next year was to use an external TNC on the D700 mini-DIN. I have a tracker2 with an SD logger mounted inside on the TTL side of the RS232 converter. That way I can take advantage of the main station antenna and not have to install a second one. I can also use the D700 in APRS mode and will not need a computer.

For logging this year I used an SD-logger and RS232 converter mounted to the back of a AA battery pack connected to my D7 operating in packet mode. The bad thing about the D7 is that it doen't have an internal clock so you don't get timestamps on the packets. I need to work on that for next year.

Sparkfun Electronics sells a micro-SD logger and Seeedstudio sells a SD logger. I have used both and they work well.

Mike George N3MUY