Search found 17 matches

by ultravista
Sun Jun 25, 2017 8:38 pm
Forum: SDR Antennas
Topic: Great experience with PAR Electronics EF-SWL
Replies: 23
Views: 5812

Re: Great experience with PAR Electronics EF-SWL

A 45 foot radiator and 9:1 balun, shouldn't this be easy to make @ home?

Is there something special about 45 feet?
by ultravista
Sun Jun 25, 2017 3:30 pm
Forum: SDR Antennas
Topic: Long Wire Antenna Performance Questions
Replies: 7
Views: 2131

Long Wire Antenna Performance Questions

Hoping someone can explain why this is happening, so that I may understand, learn, and make a better antenna. A few weeks ago I ran a 60 foot long wire antenna, 25 feet vertical and 35 feet sloping from the pole to a terminating point in the yard. The mast is ~18 feet of galvanized fence post - the ...
by ultravista
Sun Jun 25, 2017 2:46 pm
Forum: SDR Antennas
Topic: RA0SMS Miniwhip bad performance on SDRPlay
Replies: 31
Views: 10122

Re: RA0SMS Miniwhip bad performance on SDRPlay

Thank you Heinrich.
by ultravista
Sat Jun 24, 2017 10:24 pm
Forum: SDR Antennas
Topic: RA0SMS Miniwhip bad performance on SDRPlay
Replies: 31
Views: 10122

Re: RA0SMS Miniwhip bad performance on SDRPlay

Heinrich - thank you. I am in the US. I have three power supplies. http://i.imgur.com/f7Uh3hD.jpg and http://i.imgur.com/J7Zz0mA.jpg All three are approximately the same. To keep noise down, do you recommend wrapping through a toroid (if yes, which and how many turns)?
by ultravista
Sat Jun 24, 2017 3:21 pm
Forum: SDR Antennas
Topic: RA0SMS Miniwhip bad performance on SDRPlay
Replies: 31
Views: 10122

Re: RA0SMS Miniwhip bad performance on SDRPlay

The ra0sms mini whip antenna requires a 12-15V 100-150ma power supply. Around the house, I have many power supplies that are labeled as 12-15V and 100-150ma but when measured, are nowhere near the printed output. All are over voltage and current. Not one was true to the label. Not one was under volt...
by ultravista
Sat Jun 24, 2017 3:14 pm
Forum: SDR Antennas
Topic: Longwire antenna question
Replies: 7
Views: 1847

Re: Longwire antenna question

Paul - what are you using as a power supply for the ra0sms? Around the house, I have many power supplies that are labeled as 12-15V and 100-150ma but when measured, are nowhere near the printed output. All are over voltage and current. Not one was true to the label. Not one was under voltage or curr...
by ultravista
Thu Jun 22, 2017 3:46 pm
Forum: SDR Antennas
Topic: Longwire antenna question
Replies: 7
Views: 1847

Re: Longwire antenna question

Paul - I too have the ra0sms antenna. It is producing noise everywhere in the HF region, so much so that it is entirely unusable. The mast is ~ 25 feet, the bottom 15 feet is metal and the top is PVC. The mast is portable and rests on concrete - there is no real ground. The ra0sms is mounted @ the t...

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