Search found 206 matches

by vk7jj
Mon Jun 10, 2019 3:22 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 465221

Re: Receive Antenna & Impedance "Matching"

OK on the squid pole, they are great for fixed mobile or portable because they collapse to a small ultra light size and if you have a socket ready to mount one you can be on the air in less than two minutes from a standing start. Here is one in all it's glory. Forgive the lattice tower joke it's the...
by vk7jj
Mon Jun 10, 2019 3:08 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 465221

Re: Receive Antenna & Impedance "Matching"

Nice to see your refinements brought benefits; I whizzed up a single turn coupling version just for fun and the loop is pretty close to 50 ohms, haven't had a chance to do much more though. The single turn is the 1mm wire at the bottom. As you can see I'm using ceramic trimmers. I've got a few beehi...
by vk7jj
Sun Jun 09, 2019 10:20 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 465221

Re: Receive Antenna & Impedance "Matching"

That's looking encouraging isn't it, you are such an enthusiastic worker you put me to shame. Regarding the tap at 2 turns, that was chosen as a guess as my antenna has an impedance of around 300 ohms on 40m and I'm feeding the high impedance input of an RSP2, perhaps a better approach would be to t...
by vk7jj
Sun Jun 09, 2019 12:11 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 465221

Re: Receive Antenna & Impedance "Matching"

"But we are just at the beginning..." You've made more than a very good good beginning :-) Yes, the lightbulb moment for anyone using SDRuno should be when they slide the RF gain up and down with AGC on and off and notice a greater than 35dB change in system gain. If at the same time they are fretti...
by vk7jj
Fri Jun 07, 2019 12:04 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 465221

Re: Receive Antenna & Impedance "Matching"

Thank you for the reminder "HF weak signal reception in presence of noise" which was an excellent re-read, isn't it annoying how easily one tends to overlook things one has read in the past or can half remember and then not find them again. Yes, one of the many good things about the SDRplay hardware...
by vk7jj
Thu Jun 06, 2019 7:29 am
Forum: SDR Antennas
Topic: Receive Antenna & Impedance "Matching"
Replies: 114
Views: 465221

Re: Receive Antenna & Impedance "Matching"

Hi glovisol and others on this thread. glovisol, I wonder if I could interest you in single frequency preselectors. Putting aside the point that RF SNR is the ratio of the power of one's tiny little narrow wanted signal v's the power of everything else the front end of your radio is listening to acr...
by vk7jj
Wed Jun 05, 2019 9:12 am
Forum: New Users' experiences
Topic: Best antenna no good signals?
Replies: 21
Views: 137286

Re: Best antenna no good signals?

Hi K9zip, Cubic works fine on a number of different Macs I've tried it with although if you leave it running for long enough it invariably crashes with a memory leak but that's nothing to do with the issue. As Andy suggests it seems to be more than an antenna problem, I'm sure you've checked the RF ...
by vk7jj
Tue Jun 04, 2019 7:35 am
Forum: General
Topic: Parting thoughts
Replies: 16
Views: 53977

Re: Parting thoughts

Hi Gianfranco!! Nice to say hello in return to such a welcome! Apart from a fortnight of painful eye problems I've never left, I just never posted, so I've read everything pretty much daily including all your interesting articles, thank you for all of them and to everyone else. My RSP2 and RSP1A hav...
by vk7jj
Tue Jun 04, 2019 5:05 am
Forum: General
Topic: Parting thoughts
Replies: 16
Views: 53977

Re: Parting thoughts

Sheesh one needs to be careful: sdrom33, please don't think the opening line of my post above was directed at you, it was to my stalker who has hopefully moved on. You echoed my own thoughts re. long posts in general and I can't see that you have said anything that was not meant to be constructive a...
by vk7jj
Mon Jun 03, 2019 11:23 pm
Forum: General
Topic: Parting thoughts
Replies: 16
Views: 53977

Re: Parting thoughts

Posting in internet forums has become not-nice. I posted two articles on this forum some time ago which resulted in a tirade of anonymous emails sent to my private email address by a totally irrational person who ended up threatening me with just about everything he/she could think of and who submit...