Search found 206 matches

by vk7jj
Mon Jul 08, 2019 3:59 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

Hi Mike. It's not up to the task, it couldn't do it. It's a freeware version of MMANA running on Windows XP and I dusted it off for this thread so I could throw some representative figures out there for people to get an appreciation of and to use as the basis for the commentary. Not only that but as...
by vk7jj
Mon Jul 08, 2019 12:20 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

It's a rainy morning, so... The previous figures given were just begging for further calculations. Here are the figures again 30MHz radiation resistance = 2056 ohms reactance (jX) = +11343 ohms SWR = 1291 : 1 150KHz radiation resistance = 0.002 ohms reactance (jX) = -32715 ohms SWR = 1999999 : 1 -- ...
by vk7jj
Sun Jul 07, 2019 11:25 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

The W6LVP loop has been mentioned quite a few times on the Forum as an alternative to the Wellbrook. I've never even seen a Wellbrook or a W6LVP but I have had some really good fun correspondence with Larry W6LVP, the originator of that loop, which started via mutual interest in using WSPR to measur...
by vk7jj
Sun Jul 07, 2019 10:53 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

By coincidence, an excerpt from an article dated June 2017 I stumbled on during breakfast reading this morning: A simple random/long wire antenna used with a 9:1 unun is already quite wideband, although it will certainly be more resonant at some particular frequencies depending on the length. Electr...
by vk7jj
Sat Jul 06, 2019 11:13 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

Hi Thomas, The 40m vertical on the roof is a very good proxy for the TCM ... on 40m. In consideration of your earlier remarks about ground rods the photo was included to show you that the ground plane was really good one. My antenna isn't worth keeping in the air because it's too noisy even though I...
by vk7jj
Sat Jul 06, 2019 12:41 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

Hi Thomas, nice little burst of enthusiasm you've got there, the article did the same to me when I first read it :-) Here's the thing: On my 20m x 12m Colorbond shed roof there is a 10m long vertical using the roof as a ground plane. It's optimised for 40m and is resonant at 7.1Mhz. 10m is the same ...
by vk7jj
Fri Jul 05, 2019 9:15 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

On a positive note, anyone looking to build a genuine wide band vertical can, it is absolutely possible.
TC2M Gain-2.png
TC2M Gain-2.png (3.98 KiB) Viewed 10167 times
TC2M SWR 30MHz.png
TC2M SWR 30MHz.png (19.51 KiB) Viewed 10167 times
https://www.tc2m.info/

Phil
by vk7jj
Fri Jul 05, 2019 6:17 am
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

Hi Mike, yes I know, I did mention connecting to the zip cord in my first post and yes a parallel feed line is one of the pet things I keep pushing in all my posts and kudos for the inductive coupling Lankford used so as to create a balanced system. If Lankford had used coax in that circuit I would ...
by vk7jj
Fri Jul 05, 2019 3:05 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 84015

Re: Receive Antenna & Impedance "Matching"

Finally got around to resolving the issues I've been having... The inexpensive chassis mount UHF sockets on my home brew antenna splitter are faulty, the inner female part has been rotating slightly each time I inserted and screwed in the coax plug, finally causing the wires from the toroid to break...
by vk7jj
Thu Jul 04, 2019 10:47 pm
Forum: SDR Antennas
Topic: LW-MW-SW Relay Tuned 15' Noise Reducing Vertical Antenna
Replies: 57
Views: 57295

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

IMHO articles on forums are posted there in order to be discussed and commented on so that the resulting discussion raises pros and cons and teases out other related issues for the benefit of everyone. I've learned so much from making so many mistakes that I'm seriously considering making more of th...