Search found 206 matches

by vk7jj
Thu Jul 11, 2019 11:40 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

The modelling only takes a few moments, glad to help, here is 80 and 20m 80m.png 20m.png 80-20.png If you can find some zip cord or make a simple twisted pair feed from antenna wire or better still find some old TV ribbon, before you get the ferrites, it would be a waste to try to fine tune the ferr...
by vk7jj
Thu Jul 11, 2019 1:47 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 52829

Re: Receive Antenna & Impedance "Matching"

Update: Been running an RSP1A and an RSP2 side by side using CubicSDR on two separate iMacs, with audio piped directly from Cubic into WSJT-X in software using Soundflower. Have tried CubicSDR versions 0.2.4 and 0.2.5 and neither seem to permit me to choose smaller bandwidths like 250k along with an...
by vk7jj
Thu Jul 11, 2019 12:05 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Here it is again at 6m (51MHz) and UHF (432MHz) to show how a loop is good for wide band work. You'll note the gain, something you will not get from a vertical whip or groundplane, along with the improved radiation resistance and reactance. The angle of radiation is actually better than a vertical, ...
by vk7jj
Wed Jul 10, 2019 11:52 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Gianfranco, You asked me to model your pallet, here it is over real ground at a height of 16m: Overview showing current flow (the blue lines) is equal in all four sides Feedpoint is the red dot. modelview.png The pattern is omni with useful lowish angle lobes that are giving you all that nice act...
by vk7jj
Wed Jul 10, 2019 6:06 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 52829

Re: Receive Antenna & Impedance "Matching"

Update: After many days of testing, comparing the FT-857 with the RSP2 is too difficult. They behave quite differently on WSPR mostly it would appear because of their different AGC action and the results are not readily comparable. If I placed the preselector inline I would not be able to tell what ...
by vk7jj
Wed Jul 10, 2019 3:37 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

glovisol wrote:Hi Phil,
I AM SIMPLY AMAZED!!
What a skeptic!!

Hi Gianfranco, good on you. How rewarding! There surely is no silver bullet though, no single solution, there are no miracles and no free lunches!

Regards,

Phil
by vk7jj
Wed Jul 10, 2019 3:18 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Phil, <snip> Far from being offended, but really thrilled, I understand the problems with the TCM exercise: it is not small, has no gain and is more susceptible to noise intake than other antennas. You wrote about a "small" 20 m loop, but how small is small? May I ask you to expand a little on t...
by vk7jj
Wed Jul 10, 2019 2:39 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Phil: I understand that Ian has left. This topic has turned toxic and I have blocked two of the protagonists. As a result, I'll make no further comments on this topic. Hi Mike, if you think it's toxic, help turn it around, stick to commenting on the tech issues and don't let people get under your s...
by vk7jj
Mon Jul 08, 2019 11:22 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Ian, it's a good thread, it's brought out lots of things and highlighted good bits and bad bits in antennas and in us. Hi Mike, The ground plane: I don't see a reference to any ground plane in Lankford's diagram, only a wire leading to an earth rod. Let's assume the Lankford earth is a perfect ea...
by vk7jj
Mon Jul 08, 2019 4:35 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 33244

Re: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna

Hi Mike, have read your referenced article and forum through, really good fun, thanks for the ref. Clearly I wrote the bit about receive above before having the chance to absorb your ref. which I still really haven't had time to appreciate, but in saying what I did about Rx/Tx comparisons I'm not un...