In this episode, I join Martin Butler M1MRB, Caryn Eve Murray KD2GUT, and Edmund Spicer M0MNG to discuss the following:
This episode’s feature is GB0ROC Bunkers on the Air Station.
In this episode, I join Martin Butler M1MRB, Caryn Eve Murray KD2GUT, and Edmund Spicer M0MNG to discuss the following:
This episode’s feature is GB0ROC Bunkers on the Air Station.
Here are some interesting articles from QST in December 1923, 1973, and 1998.
Most, if not all new designs, are now software-defined, digital radios, but if you ever decide to build your own receiver, this might be a good article to consult. 9ZN gives a lot of good advice on how to make good coils and variable capacitors. This article caught my eye because of the call 9ZN because Bill Crane, W9ZN, a fellow who was a great CW operator, recently became an SK.
Jerry Sevick, W2FMI, wrote many articles and books about short vertical antennas. Here, he describes his design for a three-band antenna system consisting of one vertical for 80 meters and one for 20 meters/40 meters. He notes that they could be built separately. This article is worthwhile reading if you’re considering how to work more DX, especially on 80 meters.
Rob writes, “Ingenuity compensated for a limited budget in the Golden Age of Radio, and it’ll do the same today. The tools and techniques to make radio magic are everywhere. If your wallet is a bit thin, it’s time to indulge your creativity. According to Rob’s QRZ.Com page, he’s still using crummy antennas 25 years later.
The UK’s GQRP Club invites all the QRP enthusiasts to a line-up of QRP activities, to salute the arrival of the new season. Details below. There will be plenty of puny signals out there, starting this weekend, so switch your rig on, get on the bands, fly the QRP flag, and have fun.
The best overall log will be awarded the First GM3OXX Memorial Trophy.
Personally, I love the special event call signs, and I hope to get one or more in my log……Dan
In this episode, I join Martin Butler M1MRB, Caryn Eve Murray KD2GUT, Edmund Spicer M0MNG and Ed Durrant DD5LP to discuss:
This episode is kind of long, but we had quite spirited discussions about the ARRL dues increase, the RF exposure rules, and the symbol rate legislation.
This episode’s feature is KISS Technology.
30 meters was hopping the night of March 27. I worked two all-time new ones (ATNOs): 9X5RU (Rwanda) and EY8MM. 9x5RU had a strong signal into Michigan and had decent pileup going. I set up the dual receive bandscope on my IC-7610 and was able to quickly find the frequency of a station he had just contacted and quickly tuned there. It only took me three calls before they heard me.
Just a little later, I heard EY8MM calling CQ just slightly up the band. I was surprised that he hadn’t created a pileup at all. I worked him on my first call.
I have both now confirmed via Logbook of the World, bringing my total to 169 countries.
Another measure of how good the bands are are the number of QRP stations that I’ve been working lately. One such station is W3FSA in Maine. John was running about 5 W with a (tr)uSDX that he’d recently built. We had a very solid, 20-minute contact, with his signal averaging about S7 the entire time.
He paid me a nice compliment, too. He said, “I know we’ve worked before, but I can’t remember your name. You’re the teacher, though, right?”
Last night was also a good night for QRP on 30 meters. Dave, KC9FLI answered my first CQ, and I gave him a 579 report. It turns out that he was running only 1 W with a Penntek TR-35.
He was so strong, that it occurred to me that he could probably qualify for 1000 mile per watt award. QRZ.Com said that he was 293.5 miles away from me, so I reckoned that if he could reduce power to 1/4 W, that should do it.
I suggested this to him, and he agreed to give it a try. He first reduced power to 500 mW. At that level, he was between S5 and S6. Next, he reduced power to 250 mW and he was still solid copy here in Ann Arbor, MI. How cool is that?
I then did a little searching for 1000 miles/watt awards and found two of them:
Even if he doesn’t get a certificate, Dave will have the satisfaction of knowing that he completed a 1000 mile per watt QSO.
On the Elecraft-KX mailing list, an item popped up on a topic that I’ve been pondering for a while. Titled Balun necessary? Barry N1EU asked the question:
I’m planning some 40M-15M portable operation with a 44ft doublet fed with 25ft of twinlead into the KX2 ATU. Is it, or is it not, necessary to use a balun between twinlead and KX2 antenna terminals for this application?
I’ve been pondering this very question myself, as my go-to antenna for portable operation with my KX-3 is a 66-ft. doublet fed with twisted pair. I’ve just been connecting the twin-led feed line directly to the radio with a BNC-binding post adapter, but it occurred to me last summer that I should perhaps be connecting the unbalanced output of the KX-3 to the balanced feed line. The antenna seems to work just fine without the balun, but I wonder in the antenna system would be more efficient with one. At 10 – 15 W out, you want your antenna system to be as efficient as possible.
As you might expect, this question generated a lot of replies. Many of the replies simply said, “A balun is preferred,” without really giving a reason for this. Many write that using a 1:1 balun or current choke would prevent common-mode currents on the feedline. The purpose of this being to reduce the chance of the feedline radiating and causing RFI or to reduce noise pickup.
I jumped into the conversation when it was well underway and mentioned that I have been using a doublet with twisted-pair feed line. That prompted a private reply from Barry, and we struck up a conversation on the relative merits of twisted-pair feedline vs. 300 Ω twinlead and whether or not to use a balun. In one of the emails, he wrote:
FYI Dan, did a little experiment. I set up a 44ft doublet on a summit yesterday and ran some 1 watt WSPR transmissions on 40, 20, and 15m using first a 300-ohm twinlead feedline and then a twisted pair feedline (PTFE insulated, harvested from surplus CAT5e cable). I’ve always been intrigued by the super lightweight twisted pair and several years ago used it once with very good results (high score in 2014 QRPTTF/SOTA event). But I always wondered about the loss involved, especially with the high SWR encountered in a non-resonant antenna.
I lacked sufficient time on the summit to be very thorough and methodical but I believe the data is valid. 30-45 minutes separated the transmissions for the different feedlines.
- 40m – 24 reports for both – twisted pair averaged -3.75dB down from twinlead
- 20m – 27 reports for both – twisted pair averaged -1.56dB down from twinlead
- 15m – 13 reports for both – twisted pair averaged -4.15dB down from twinlead
Perhaps one day I’ll do a more thorough and methodical test but I think these results show that PTFE twisted pair is a viable balanced feedline and makes for an ultralight option for SOTA activation, although twinlead is preferred when weight is not an issue.
Other equipment used included an Elecraft KX2/ATU and Android phone running WSPR Beacon. The 300-ohm twinlead was connected using a homebrew dual FT140-43 core 4:1 Guanella current balun and the twisted pair was connected using a homebrew FT140-43 common mode choke (12 turns).
I should probably do some of my own testing. While scouring the shack for stuff to take to a hamfest a couple of weeks ago I ran across some quality 300 Ω twinlead, so I could make up a 66-ft. doublet with the twin lead feedline. I also have ferrite cores and try winding the twisted pair feedline around it to see if that makes any difference. Barry’s test show that the twin lead is more efficient, but twisted pair is easier to handle and does wind up into a smaller and lighter package for transporting to and from a POTA or SOTA site.
It would be interesting to do some testing with the 44-ft. doublet. In general, of course, the more wire in the air the better, but less wire again makes it more manageable. I’m going to have to download WSPR Beacon to my Android phone, too. In any event, it looks like I’ll have a lot of fun stuff to play with this summer when I can get out and do some activations.
A couple of evenings ago, I had a couple of interesting contacts with stations running QRP. That wasn’t the most interesting thing about the contacts, though.
The contact with Kyle, KN6KJK, was remarkable for a couple of reasons:
My next contact was with Jerry, KI4PS. He was operating an FT-818 at 5 W. The reason that this contact was interesting is that Jerry cut the contact short, complaining about QRM. There was indeed a signal operating very close to our frequency (see screenshot at left). I’m going to guess that that signal was about 250 Hz down from our frequency of 7028 kHz.
I didn’t hear that signal at all. I had my Flex 6400 filter set to 250 Hz, meaning that the QRM was outside of the passband. That’s a real tribute to the Flex filtering algorithms.
Finally, I worked a guy a couple of days after Christmas who has the following on his QRZ.Com page:
Don’t get the chinese virus vaccine it may contain ID2020 chip as immunity passport. It is part of the mark of the beast!
Seriously??
I had hoped that ham radio operators had more sense, but I guess not. My take on it is that even if there was an ID2020 chip, it wouldn’t be available due to the chip shortage.
I’m on a lot of ham radio mailing lists, and people are constantly sending me interesting things to read and to watch. Here are some of the coolest from the past couple of weeks…..Dan
This is very cool. Adam, K6ARK, has designed a surface-mount version of the Pixie transceiver. (There are many different designs, but to get an idea of what a Pixie is, here’s a circuit description of a more recent design.) What’s really amazing about this video is the number of contacts that Adam makes with this little radio out in the boonies. I mean we’re talking less than a watt output and a receiver that’s as wide as a barn door. Very impressive.
The Absolute Beginner’s Guide to the NanoVNA by Martin Svaco, 9A2JK is a wonderful introduction to this cool, little instrument. It not only includes instructions on how to use a NanoVNA, there is a short history of the instrument and the different version out there as well as a brief theory of operation. If you have a NanoVNA, you should get this guide.
I know that this is a little late for this series of ISS SSTV transmissions, but I’m sure that they’ll do it again sooner or later.
The GQRP Club, the British QRP club, has released a detailed agenda for its 2020 Online Convention, taking place on Saturday 5th and Sunday 6th September.
The online event, which replaces the club’s annual GQRP convention at Telford due to current Covid-19 restrictions, is open to existing members. There is a special rate for non-members which will include GQRP Club membership until January 2022.
The two-day event comprises a series of online presentations and knowledge-sharing meetings where people can share ideas.
The packed presentation list includes:
There will also be range of knowledge-sharing sessions, including “Using Antenna analysers” with Heather M0HMO, “Running a QRP DxPedition” with Dom M1KTA, “Battery technology for QRP portable” with Bill G4ERV, “Omni Directional antennas” with John G8SEQ and many more.
The event costs £4 for GQRP club members. Non-members can also sign up for the event and join the GQRP club for just £10 (or £17 for international participants).
To sign up for the event just go to the Eventbrite sign-up page at: https://www.eventbrite.co.uk/e/gqrp-club-2020-online-convention-tickets-115417887007
For more information and to view the full event schedule see http://www.gqrp.com/convention.htm
I received this literally minutes ago from Graham, G3MFJ, the GQRP treasurer:
The GQRP Club officers had to make the difficult decision to cancel the QRP Convention which was to be held in England over the weekend of 5th and 6th, September 2020.
However, we have decided to run an Online Virtual Convention in its place. Our intention is to run this over the online platform Zoom . (Zoom is a free online application which runs over smartphones, tablets and computers on most platforms for all those wanting to join the convention)
We would like to judge the possible response to our Convention, which would of course be open at a small cost to members of the GQRP Club all over the world, and will also be available to non-members at an increased cost.
If you are interested in attending the Convention please would you mind COMPLETING OUR SURVEY. The information you give us will help plan and organise the event.
The survey sets out the cost and tries to find out a bit more about what would be of interest to you and whether you can help in any way in making this first ever online QRP Convention a success. There has never before been an event which potentially all our members could attend at minimal cost!.