Search found 53 matches

by OH2BUA
Thu Jun 14, 2018 3:00 pm
Forum: SDR Antennas
Topic: Newbie RF frontend protection Qs
Replies: 26
Views: 3060

Re: Newbie RF frontend protection Qs

18 MHz only?!


Above 18MHz, my friend. I'm monitoring between 1.8-50Mhz (with that antenna), and I feel that on 6m I'm almost deaf.

I have other gear going nicely over 1GHz.

73, Jukka
by OH2BUA
Thu Jun 14, 2018 11:12 am
Forum: SDR Antennas
Topic: Newbie RF frontend protection Qs
Replies: 26
Views: 3060

Re: Newbie RF frontend protection Qs

Thanks for your replies. I'm planning for a 'major upgrade' for my 2*1N4148 protection system, to go for 4*1N4148. That's mainly to push down the unwanted capacitance, as I feel that my monitoring system is a little bit hard-in-hearing above 18MHz. https://www.pskreporter.info/pskmap?preset&call...
by OH2BUA
Tue Jun 12, 2018 2:52 pm
Forum: SDR Antennas
Topic: Newbie RF frontend protection Qs
Replies: 26
Views: 3060

Re: Newbie RF frontend protection Qs

Is it for sure proper way to calculate two 1N4148 diodes in series simply like 0.7 + 0.7 = 1.4V ? If we deploy 2 volts over that, is the forward voltage over one diode 1V... or perhaps just plain 0V? (Like to hear that 1.4V is ok calculation... as also the (unwanted) capacitance is halved.) 73, Jukka
by OH2BUA
Mon May 21, 2018 11:43 am
Forum: SDRplay related
Topic: RSPduo dual API question
Replies: 6
Views: 551

Re: RSPduo dual API question

Thanks for your prompt answer.

In case you happen to need a betatester for ExtIO, I can volunteer as I 'seriously' need it.

73, Jukka
by OH2BUA
Mon May 21, 2018 6:02 am
Forum: SDRplay related
Topic: RSPduo dual API question
Replies: 6
Views: 551

RSPduo dual API question

Dear Support, (sales not needed as my first RSPduo is already on shipment to me:) could you please clarify a thing from the Introduction-document, pages 3-4, regarding the new API concept: Do I understand right, that it would be possible operate let's say Tuner 1 with SDRuno and Tuner 2 with HDSDR -...
by OH2BUA
Thu Apr 12, 2018 6:08 am
Forum: SDRplay related
Topic: RSP2A and RPi 3 B+
Replies: 15
Views: 2535

Re: RSP2A and RPi 3 B+

Hi,

I have something to ask about the RasPi-image:

1) Is it based and compatible with some well-known distro? Raspbian I hope?

2) Is there included a thing which allows one to receive USB by using command line interface?

73, Jukka
by OH2BUA
Tue Apr 10, 2018 4:26 pm
Forum: SDRplay related
Topic: Front end protection during TX?
Replies: 5
Views: 882

Re: Front end protection during TX?

@SDRFreq,

RSP2 HiZ-input can be used under 30MHz only, it's 1000 ohm balanced and there's no bias-T in it.

Very deaf it is not, have look at world Top 20: https://www.pskreporter.info/cgi-bin/pskstats.pl

73, Jukka
by OH2BUA
Tue Apr 10, 2018 6:31 am
Forum: SDRplay related
Topic: Front end protection during TX?
Replies: 5
Views: 882

Re: Front end protection during TX?

I have protected my RSP2 HiZ-input by using two pieces of 1N4148 diodes, in opposite polarities. RX antenna is a Double-KAZ (LF-MW-160m). TX source is OCF Windom, 30 meters separated, 100 watts out, 1.8-30MHz). This has been enough protection - but no warranty by me for anybody. (In rare situations ...
by OH2BUA
Sat Jan 06, 2018 3:16 pm
Forum: General
Topic: RSP2 RF Protection Question
Replies: 11
Views: 3973

Re: RSP2 RF Protection Question

Thank you Jon for the answer! For 50 ohm unbalanced inputs there are several off-the-shelf products as well as DIY receipts available about how to protect the RX. But how about the Hi-Z-input? I don't know any commercial products for that. I have handled it like this: The GND is connected to a prope...
by OH2BUA
Sun Dec 31, 2017 11:45 am
Forum: General
Topic: RSP2 RF Protection Question
Replies: 11
Views: 3973

Re: RSP2 RF Protection Question

Dear Tech_Support,

RSP2 does have three antenna inputs, which is a really great thing.

Are they all equally vulnerable for high RF levels - or just the 'selected' one?

73, Jukka

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