Archive for February, 2011
ARISSat-1 was supposed to be launched from the International Space Station this week, but it has been postponed. I have this vision of one of the astronauts rolling down the window on the station and chucking the satellite overboard. It probably doesn’t really work like that.
The ARRL reports that there is a Spectrum Management Bill being developed in the House Energy and Commerce Committee. H.R. 607 would reallocate existing amateur radio spectrum of 420-440 MHz for other uses. It seems silly for Congress to put a specific frequency range into a bill as they are in no position to understand the impact.
One of our local Scouts, Jake W0JAK, is the star of a YouTube video on how to solder.
When I wasn’t looking Amateur Radio Newsline disappeared from my podcast feed. Apparently, they had to change servers to solve a technical problem. If you are missing ARN, go resubscribe using iTunes or other podcast software.
73, Bob K0NR
I recently commented on the ARRL Log Book of the World when they turned on support for the VUCC Award. This was a long time in coming and is a great addition to the program.
About a week later, I was poking around my qrz.com page and found that there are 32 QSOs sitting there waiting for me to confirm them. What? QSOs on qrz.com? It seems that they have added a “logbook” feature which supports keeping a log of radio contacts and verifying these contacts with other radio amateurs. I participated in the ARRL January VHF Sweepstakes and some of the contest participants uploaded their log to qrz.com, which caused these QSOs to show up in my logbook.
So now there are at least 3 online amateur logbooks available: eQSL, LoTW and qrz.com. So far, I have only paid attention to LoTW, uploading all of my contacts made since 2002. I have ignored eQSL since these contacts do not count towards ARRL awards. Yes, that does mean I am old school and think that DXCC, VUCC and WAS from the ARRL are the real deal and anything else is an imitation. CQ Amateur Radio is accepting eQSL confirmations and has a decent awards program, but I haven’t focused on any of those yet.
You can see what is going to happen…the amateur population will split across these different logbooks and it will be difficult to transfer “credit” between them. You’ll have a mishmash of confirmed QSOs that include the good old paper variety and several different electronic logbooks.
I am not sure what to do about this but I’ll probably just focus on LoTW. What do you think?
73, Bob K0NR
I recently received this question via email from Dave N0MUA:
Bob, I ran across your pictures mountain topping on Colorado peaks, thought if anyone could answer this it would be you and your group. We run on 146.52 here in Coffeyville KS. and a group of us have brought up the question how far east can a mobile atop Pikes Peak be heard on 146.52 FM? The mobile would be mine running a Icom V8000 into a Tokyo HI power amp at 375 watts LMR 400 coax to a Cushcraft 13B2 beam pointing to the east.
This is one of those how far will my signal go? questions that always gets my attention. Other folks may find this interesting, so I decided to spend some time on the topic and post it here. I am assuming we are talking about tropospheric propagation and not something more exotic such as meteor scatter or sporadic-e skip.
The (incorrect) conventional wisdom is that VHF propagation is “line of sight”, extending a bit beyond the optical horizon. From Wikipedia, we find that the distance to the optical horizon can be approximated by:
d = √(1.5 h)
where d is the distance to horizon in miles, h is the height of the observer above ground in feet
Pikes Peak reaches to 14,110 feet above sea level. The elevation of the surrounding area varies but since Dave is asking about propagation into Kansas, let’s use a typical elevation of eastern Colorado (4500 feet). This gives us an optical horizon equal to the square root of (1.5 x 9610) = 120 miles. Yes, this is an approximation, so feel free to knock yourself out with a more precise calculation.
It is interesting to note that there is a community 30 miles west of the Kansas border called Firstview, CO that is supposed to provide the first opportunity to see Pikes Peak when traveling from the east on Highway 40. Firstview is about 135 miles east of Pikes Peak, so the 120 mile calculation is in the right ballpark.
The ARRL web site says that the radio horizon is about 15% longer than the optical horizon, so that means our line-of-sight radio horizon is about 1.15 x 120 = 138 miles. I’ve operated from the summit of Pikes during the ARRL June VHF QSO Party and the Colorado 14er Event and working stations on 2 Meters at this distance is not difficult. To be more specific, I worked the Mt Sunflower crew (highest point in Kansas, 160 miles) from Pikes Peak on 2 Meter FM using a 25 Watt mobile and a not-very-well-positioned 1/4-wave antenna on the SUV fender.
I pulled up the distance records for the Colorado 14er Event and found that the best DX using 2 Meter FM is when Phil N0KE on Mount Bross worked Larry N0LL in Smith Center, KS at a distance of 375 Miles! Clearly, we are well beyond line of sight for this radio contact. N0LL has a very capable VHF station on his end and I believe N0KE was using a decent Yagi antenna and was running some power(~200W?). Still, this contact was on FM which is not that great for weak signal work. While Pikes is on the Front Range of the Rockies, Mount Bross (14, 172 feet) sits back some distance, about 60 miles west of Pikes Peak. (I have also worked N0LL from Pikes using 50W and a single 2M9 yagi on SSB with no problem during VHF contests.)
Also during the Colorado 14er Event, Phil N0KE (and Jeff N0XDW) on Mount Bross worked W7XU in Parker, SD on 2 Meter CW at a distance of 551 miles. Keep in mind that as the signal strength fades, SSB has a serious advantage over FM and CW is even better! So for squeaking out the marginal contacts, CW is the way to go.
Dave asked about working Pikes Peak from Coffeyville, KS using 2 Meter FM. I had to look up where Coffeyville is and discovered that it is way the heck over on the east side of Kansas, maybe 50 miles from Missouri. I estimate that Coffeyville is 525 miles from Pikes Peak. To get back to Dave’s question, making a contact from Pikes to Coffeyville on 146.52 MHz FM is not likely. Maybe if we got some exceptional tropospheric propagation…but I think even then it would be unlikely to complete the contact using FM.
But you never know what might happen on VHF. That’s what makes it fun.
73, Bob K0NR
Today, I had the privilege of presenting the Technical Service Award (ARRL Colorado Section) to the 285 TechConnect Radio Club. I have to tell you…this club is an excellent example of how to advance the hobby of ham radio. They have figured out that providing technical education is a great way to attract members and assist the local amateur radio community.
Here’s a photo of me handing Bill N0CU, club president, the award:
At the meeting, Bill also did an excellent presentation on grounding issues in amateur radio stations. This is a complicated topic that Bill handled very well.
Here’s the announcement of the award:
We are pleased to announce that the 2010 Technical Service Award from the ARRL Colorado Section has been awarded to the 285 TechConnect Radio Club ( http://www.na0tc.org/ ). In past years, this award has been presented to individuals that have provided exceptional technical service to the amateur radio community. This year the award goes to the entire TechConnect club for their collective contribution to the Colorado amateur radio community. In particular, the club sponsored the all day “2010 Fall TechFest”, with a great line up of technical and operating presentations (http://www.na0tc.org/TechFest_2010_Workshop_Materials.htm ). The club also sponsors the TechNet that meets at 7 PM local on Tuesday nights on the Colorado Repeater Association 147.225 MHz repeater. These activities have made an important contribution to technical education in the Colorado section.
Our thanks and congratulations goes to the entire club with special thanks to Steve Finch, AI0W, Technical Specialist, Colorado Section for his personal leadership and contribution to this effort.
Jeff Ryan, K0RM
Section Manager, ARRL Colorado Section
Bob Witte, K0NR
Technical Coordinator, ARRL Colorado Section