Showing posts with label antenna. Show all posts
Showing posts with label antenna. Show all posts

25 January, 2026

Do deer like antenna wires?

Our garden is frequently visited by roe deer. They like to trek along the little brook that runs at the edge of the garden. Usually that has few consequences.

But this weekend as I was about to contact stations during the CQ160CW contest, I noticed that nobody could hear me. I heard many stations, but nobody seemed to hear my signal.

08 October, 2019

6 m Antenna Inspiration

It's nice to see that my antenna article in Amatørradio no. 3 this year has inspired others. In no. 4, LA1AEA, Alfred, has written about how he made his own. It helped him try the 6 meter band this summer. Given his location in the very far North of Norway (Finnmark), I'm impressed by contacts that he had all the way to Greece, 3500 km away.

He writes: "LA3ZA Sverre Holm wrote an interesting article in no 3, 2019 with title "A Moxon summer antenna for 6 meter." I was inspired to try myself with some simple materials that I had available. For a long time I have considered the 6 m band to be unusable from here way up North. But this shows how wrong one can be."




This blog post first appeared on the LA3ZA blog.

25 June, 2019

A Moxon for 6 meter

My new 6 m antenna is in the Norwegian ham radio magazine Amatørradio this month and the two first pages are shown below. The title is "A Moxon summer antenna for 6 meter". A very short version is here.

The antenna builds on the design of L. B. Cebik, W4RNL in QST June 2000 - "Having a Field Day with the Moxon Rectangle". That design can be found in the moxgen program which may be downloaded from AC6LA. My design frequency was 50.2 MHz - in order to cover the CW band and FT8 at 50.313 MHz.

The design with crossed glassfiber rods was inspired by that of Anthony Good, K3NG - "Homebrew Lightweight 6 Meter Moxon".

23 February, 2017

Comparing two antennas with WSPR

Ultimate 3S with 5-band relay module in front,
variable LM2596 power supply (with voltmeter) for
the power amplifier behind left,
a variable LM2596 supply set for 5 Volts for the Ultimate 3S
in the middle, and the antenna switch to the right in the back.
WSPR - The system for Weak Signal Propagation Reporter makes it easy to compare antennas if your transmitter can instantly switch antennas. The system shown here can send on antenna 1 for almost two minutes and then switch immediately to antenna 2 for the next transmission.

The Ultimate 3S already has software that supports that and application note 3 from QRPLabs (Controlling additional relays using the Ultimate3S “Aux”) describes how. I built mine following that note and the experience from EA1CDV.

The circuit is controlled from pin D7 and consists of a transistor, a relay, a resistor and an electrolytic capacitor. In addition I have two LEDs that indicate which antenna which is in use. In the first picture the green LED in the back right under the BNC antenna connector shows that antenna 1 is connected.

20 February, 2014

Worst snow winter since 1958 and an indoor Yagi antenna

Norway has had its fair share of precipitation this winter. Along the coast most of it has been in the form of rain. But that is different in the mountains. Our cabin at 800 m above sea level is now about to disappear in the snow and we can hardly see out of the windows anymore. This is a result of having had to shovel the snow off the roof three times so far this winter. And there is yet more to come.

They say that one has to go back to the winter of 1958 for more snow than we have had this winter, and we are still only in February. The snow has also given us an unexpected problem. Our digital TV signal is now gone.

01 August, 2012

Vertical antenna on a turf roof

A vertical wire antenna based on a MFJ-1904H 6.7 m (22 feet) telescopic fiberglass pole as shown here is easily tuneable for all bands from 40 m to 10 m. Here it is placed on top of a turf (sod) roof with quarter wave radials for all the 7 bands going to each of the two sides sloping down as they follow the contour of the roof. The antenna seems to work satisfactorily at least on the 30, 20, and 17 m bands which I have been able to test so far.

A turf roof is a traditional Scandinavian type of green roof covered with grass. It dates back to the Viking age and before. In modern times it has seen a renaissance in e.g. mountain cabins.

But how does the turf affect the antenna or to pose the question more precisely: Can it be used to improve the ground plane and the antenna's performance?

09 July, 2011

Wire antennas for DX: Pair of doublets

At my summer cottage (58° N, 9° E), I have two crossed doublets with their centers on the top of a mast as shown in the image. Of course, I would like to have had a rotatable beam antenna, but lacking that, this is a wire antenna substitute with acceptable performance. I use them for DX-ing and participation in contests like the IARU HF contest in July. The first antenna is a 26.8 m (88 feet) doublet and the second one at 13.4 m (44 feet), which was erected last summer, is half this length. Switching between the antennas sometimes makes a difference of 4-5 S-units of signal strength, but usually less.