Search found 206 matches

by Andrew (grayhat)
Sat Nov 12, 2022 7:56 am
Forum: Questions & Advice
Topic: Perhaps goofy antenna idea
Replies: 37
Views: 1616

Re: Perhaps goofy antenna idea

Jock, any update regarding outdoor antennas ?
by Andrew (grayhat)
Wed Nov 09, 2022 8:07 pm
Forum: Log Sharing & Broadcast Frequencies/Schedules
Topic: Strange afternoon MW DX flare (5,500 and 7,500km!)
Replies: 5
Views: 223

Re: Strange afternoon MW DX flare (5,500 and 7,500km!)

I obviously like it to bits! :) No, seriously, it's not having any severe highpass/reduced sensitivity issues typical for ham transceivers on MW/LW and it has all the nice tools one would want in a MW DX radio (particularly passband tuning and notch filter), being an SDR and showing me faint carrie...
by Andrew (grayhat)
Sat Oct 22, 2022 8:00 pm
Forum: General Discussion
Topic: The Belka (-DSP/-DX) appreciation thread
Replies: 18
Views: 2020

Re: The Belka DSP/DX appreciation thread

13dka wrote: Sat Oct 22, 2022 6:19 pm Got the new Belka (2022 model) today, went to the dike with it... <3 <3 :mrgreen:
hmmm... sounds like you had some wild fun :D
by Andrew (grayhat)
Sun Oct 16, 2022 8:30 am
Forum: General Discussion
Topic: Another unidirectional small loop: the Coplanar Twin Loop
Replies: 25
Views: 879

Re: Another unidirectional small loop: the Coplanar Twin Loop

as for the CTL, did you consider changing the size of the sides ? I mean, for example, making the vertical size 1/2 of the horizontal (or the other way around) while keeping the same total perimeter
by Andrew (grayhat)
Sat Oct 15, 2022 7:16 pm
Forum: General Discussion
Topic: Another unidirectional small loop: the Coplanar Twin Loop
Replies: 25
Views: 879

Re: Another unidirectional small loop: the Coplanar Twin Loop

Welcome to the forum, qrp-gaijin! Hope you guys tell me when it's time to charge my little dremel tool. :mrgreen: ~20dB more gain / less losses at little more than 1/2 the size of the SULA sounds pretty intriguing, even though the overall coverage seems to be pretty small (7-21Mhz?). ...check if it...
by Andrew (grayhat)
Sat Oct 15, 2022 4:00 pm
Forum: General Discussion
Topic: Another unidirectional small loop: the Coplanar Twin Loop
Replies: 25
Views: 879

Re: Another unidirectional small loop: the Coplanar Twin Loop

forgot (and OT) do you know what happened to Jim's ham forum (the radio board) ? I know you were a member there, and there were a lot of cool folks, but then, it went suddenly "poof" <sigh>
by Andrew (grayhat)
Sat Oct 15, 2022 10:28 am
Forum: General Discussion
Topic: Another unidirectional small loop: the Coplanar Twin Loop
Replies: 25
Views: 879

Re: Another unidirectional small loop: the Coplanar Twin Loop

first of all, at the moment I'm busy helping some relatives picking olives from trees, so please forgive me if I delay my replies; also, as you can guess. I've no way to run NEC simulations here :D (note: did you know that ezNEC is now free ? https://www.eznec.com/ ) ... anyhow, your simulations are...
by Andrew (grayhat)
Fri Oct 14, 2022 5:08 pm
Forum: General Discussion
Topic: Another unidirectional small loop: the Coplanar Twin Loop
Replies: 25
Views: 879

Re: Another unidirectional small loop: the Coplanar Twin Loop

forgot, (yes, still ferreting around <sigh>); try the following: load the CTL model, remove the cap/resistor from the outer loop and replace the cap in the inner loop with a resistor (530 Ohms like the SULA will do), now run the NEC model, done so, change the inner loop size and check the result, do...
by Andrew (grayhat)
Fri Oct 14, 2022 4:49 pm
Forum: General Discussion
Topic: Another unidirectional small loop: the Coplanar Twin Loop
Replies: 25
Views: 879

Re: Another unidirectional small loop: the Coplanar Twin Loop

I'm in a hurry, so I'll keep this short; first, that loop and dipoles setup somewhat recalls at large a yagi (dipoles), did you try changing the size/spacing of the dipoles ? Then, about the CTL, I started wondering if it may be used as a TX antenna, in such a case it would be interesting for lower ...
by Andrew (grayhat)
Fri Oct 14, 2022 2:36 pm
Forum: General Discussion
Topic: Another unidirectional small loop: the Coplanar Twin Loop
Replies: 25
Views: 879

Re: Another unidirectional small loop: the Coplanar Twin Loop

Thank you, ran the model and it behaves as expected, I just changed the "GN" card to put the antenna over real ground and not in free space ("GN 2 0 0 0 13 0.005") the results are pretty good, but the impedance is around 2 Ohm which means that, to couple the antenna to a receiver...