Search found 93 matches
- Thu Feb 08, 2024 3:03 pm
- Forum: Questions & Advice
- Topic: Wet weather antennas
- Replies: 3
- Views: 5325
Re: Wet weather antennas
Hi Andrew, I use wire antennas for my QRP work. I did one outing with my antenna exposed to steady rain (I sat in the truck with feedline running in through the door seal after a generous drip loop). I noticed two issues. First, it was the only time I recall having RF in "shack" issues whi...
- Sat Jan 13, 2024 7:48 pm
- Forum: Questions & Advice
- Topic: KM4CFT Antenna kit 30/17 meters
- Replies: 4
- Views: 7837
Re: KM4CFT Antenna kit 30/17 meters
Hi Folks, please excuse my ignorance on this but several weeks ago Tom did a review/activation on the KM4CFT EFHW/EFRW antenna kit where he was able to activate most of the bands from 40-10 using this antenna kit with a 30M and 40M link. He was able to to use the 30M wire to activate 17M. I current...
- Thu Sep 28, 2023 4:11 am
- Forum: Questions & Advice
- Topic: 9:1 unun 20m
- Replies: 3
- Views: 3300
Re: 9:1 unun 20m
I want to use my 9:1 unun with my 20m QCX mini. What length wire recommendations? 9:1 ununs are typically used with random wire antennas, which are intentionally non-resonant. So, you would need a tuner to match the antenna to your QCX. An advantage of the random wire is its ability to be matched w...
- Sat Sep 23, 2023 9:03 pm
- Forum: General Discussion
- Topic: Battery for QRO operations
- Replies: 5
- Views: 5062
Re: Battery for QRO operations
Hi Matteo, The LiFePO4 batteries that I use have a built-in battery management system (BMS) to protect the battery. In addition to a low voltage cut-off (battery charge expended), they have a high current cut-off. If you draw more than the rated current, the BMS will shut down the battery. After pro...
- Tue Aug 22, 2023 2:35 pm
- Forum: General Discussion
- Topic: CW Morse SP4 paddle
- Replies: 8
- Views: 10990
Re: CW Morse SP4 paddle
The second key from the right is a BaMaTech TP-III. https://www.bamatech.net/morsetasten/ba ... y-rot.html
- Wed Jul 05, 2023 3:34 pm
- Forum: General Discussion
- Topic: Best Practices for an EFRW Setup
- Replies: 18
- Views: 9601
Re: Best Practices for an EFRW Setup
Mike, you're looking at it just from the point of view of "nasty effects during transmission", that isn't the only way, let me expand it; first of all there's nothing like "power levels" when it comes to common mode currents, the point is that a feedline (coax) should work as a ...
- Tue Jun 27, 2023 4:09 pm
- Forum: Questions & Advice
- Topic: JNC cs-818 tuner
- Replies: 16
- Views: 5919
Re: JNC cs-818 tuner
Brian, probably I oversimplified, what I mean is that one may like being able to jump on a non harmonically related band, so just by changing the EFHW length to a "good" one for a random and changing the tap to 9:1 we would then be able to jump on (say) the 30 meters band or whatever else...
- Tue Jun 27, 2023 3:16 pm
- Forum: Questions & Advice
- Topic: JNC cs-818 tuner
- Replies: 16
- Views: 5919
Re: JNC cs-818 tuner
Andrew - It should be possible to wind 9:1 & 49:1 transformance ratios on the same toroid, using different tap points. A few thoughts: First, if your ~66 ft radiator for 49:1 is tuned low in the CW range for 40m, it should be resonant on 20m, 15m, and 10m for CW. It would also likely be workable...
- Sun Jun 18, 2023 2:44 pm
- Forum: General Discussion
- Topic: Best Practices for an EFRW Setup
- Replies: 18
- Views: 9601
Re: Best Practices for an EFRW Setup
Hi Mike, The Tufteln 9:1 with 35 ft radiator is one of two antennas that live in my KX2 field kit. The other is a Packtenna 9:1 with a 71 ft radiator. I can tell you about my personal experience, but I claim no special knowledge. For context, I use this equipment for POTA activations, and I nearly a...
- Tue May 23, 2023 1:04 pm
- Forum: General Discussion
- Topic: New QRP Labs Radio - QMX
- Replies: 5
- Views: 5492
Re: New QRP Labs Radio - QMX
My timing isn't that great - my QCX-mini kit arrived last week! I'm hoping that Hans makes a high band (20-17-15-12-10) version too. When he presented the QMX at the Four Days in May (FDIM) conference, Hans specifically noted that he expects to put out a high band version of the QMX. He seems to ha...