This blog generates a stream of email – some of which are the basis for posts you’ve read. Others update me on material presented in previous posts. Here are some of those:
A Tree-Mounted Yagi
Last months’ post about Leroy N7EIE and his uniquely mounted triband Yagi may have jinxed him. Larry has the good fortune to be surrounded by trees that make my tall pines look like shrubs. Being the practical individual that he is, he saw them as organic towers – just as I would. In a follow-up email, Larry reminds me of Newtonian mechanics with photos of his Yagi’s submission to gravity. Actually, it was the tree limbs that fell in Washington state’s worst ice storm in 40 years.
I learned that with a vengeance last week during Washington’s worst snow/ice storm up here in 40 years.
As you can see from some of these pictures, I have about 30+ limbs down that weigh 30 lbs or more. Of those, about half a dozen are 50 lbs or more. Of those, I had 2 at 100 lbs or more, and they both hit Jupiter 2 and the shed at the same time.
Bottom line: Jupiter 2 totally trashed, my shed crushed like a matchbox, and J2J (Jupiter 2 Jig): kindling. About $1,000 in total damage in the back yard.
Good news: My house is undamaged and I’m uninjured.
Handiwork by W3CUV
In September I posted a brief write-up of a very inexpensive digital capacitance meter kit that I built. Mine is still unhoused but not un-used. I enjoy having it.
Not long after that posting, I received an email with photos from Neal W3CUV who shows me the right way to put the finishing touches on a kit. Neal told me that he enjoys the mechanical aspects of his radio projects as much as the electronics and it sure shows:
I asked Neal about some of the details regarding construction and received the following:
I made the square hole for the LED module with a nibbling tool and hand files.
Same for the slide switch. It’s very labor intensive, but I’m retired and have
lots of time :-)
I pulled the tape off the LED module and made a lens out of plastic from a
CD jewell case (more filing). The LED is plenty bright that way.
I formed the hold-down bracket for the battery with blocks of wood (see pix).
Several other small projects I’ve made, including the Norcal FCC-1 and the
KD1JV Tenna Dipper are just like this.
The Cap meter draws abt 25 milliamperes, so I put a 110 ohm resistor in series
with the output of a 9 volt wall-wart. (no load voltage=15 V.) This drops the
voltage under load to abt 9.4 volts, and is just right for a float charge
(4-5 mA) for the NiMH battery.
80m conditions at 5Z4EE and 4W6A
Regular readers here may be aware that my attraction for this hobby revolves around the magic of radio. Although I understand how it works, the allure is just the same for me as it was when I was a kid. One of the ways this magic most clearly manifests itself for me is in the category of DXing. Particularly low-band DXing.
I’m still learning propagation subtleties of the 80-meter band and am regularly awed by what’s possible there. For years I was under the impression that DXing on 80m required a huge antenna at one end of the path. In other words, I could DX with a dipole if the other guy had a 4-square.
That was my impression…my false impression.
I recently emailed two excellent DXers whom I’ve worked on 80 meters recently: Sig 5Z4EE, and John 9M6XRO who was part of the 4W6A team. Both of them put potent signals here into south Texas from far parts of the globe on what I used to think of as a “local” band. I asked them for details of their 80m antennas. Here are their replies:
Sig 5Z4EE (Kenya):
Hi, John. I have your QSL on my wall.
My main antenna for 80m now is an MFJ-2990 43 foot vertical on the chimney of my two storey residence. I retrofitted it with the unun for 43 foot verticals from DX Engineering. I don’t have the room to put a vertical on the ground. I have plenty of radials from the DX Engineering radial plate on the chimney four radials for 160 and at least 60 radials for 80 and 40.
Last winter I used the Cushcraft MA8040v vertical on the chimney. I changed to the 43 foot vertical in the hope of gaining 160 meter capability. As it has turned out, the solar flux has risen to the point where 80 meters is no longer viable to North America from my QTH. Since the solar flux will probably stay over 100 for the next couple of years, I think I am finished on 80m at 5Z4EE. I will be gone from Kenya by 2014.
Last week I put up an 80 meter dipole hoping to do better on 80 but all I can really hear is Europe, and then not as well as last year.
I did manage to work KH6 and many other countries in the CQWW on 40m with the 43 foot vertical, so at least I know it is working on 40.
I intend to be in the ARRL DX and the WPX contests in the next few months and again in the CQWW later this year. I hope to work you again this year.
John 9M6XRO/4W6A (Timor-Leste):
Happy New Year to you and yours!
Not much to tell about the 80m antenna we used at 4W6A. Here are the
bare facts :
80m Quarter-wave wire vertical on 18m Spiderbeam pole with 16
quarter-wave ground radials
As the 18m fibreglass pole was too short to accommodate the approx 66′
of insulated wire we used for the quarter wave element we had to coil
some of it around the mast to take up the ‘slack’. The radials were laid
out on he ground but as we did not run any of them into the sea they
were all basically within the landward side semicircle. I have attached
a photo which shows the 18m fibreglass pole in the foreground so you can
see how close we were to the beach – it was mounted just above the high
water mark – and this played no small part in how potent a signal we
were putting out :-)
The operating shack was in the 2-storey hut which you can see behind the
18m pole, approx 100′ from the antenna feedpoint. We were feeding it
with 50-ohm RG-58 coax, straight in, SWR of less than 1.5:1 across the
band without an ATU or matching unit. This would indicate that the
ground/radial system was rather poor. With a really good ground system
the impedance should have been lower but I guess we got away with it
because we were so close to the sea with a clear take off in the right
I have used similar ants at inland locations but in those circumstances
a good ground system takes on much more importance. An inverted L has
done well for me on 80 and 160m but the main thing is to get as much of
the antenna vertical as possible and again have the best ground system
you can manage.
Leroy, Neal, Sig and John – thanks so much for taking the time. 73 to all and see you down the log!