Search found 494 matches

by g1hbe
Sun Feb 07, 2016 8:07 pm
Forum: SDRplay related
Topic: Strange behaviour on 20m
Replies: 5
Views: 4987

Re: Strange behaviour on 20m

Hello Sasan. The third screenshot looks very much like the shape of Tetra (or similar) which is used in the 300 - 400 MHz area. As the SDRPlay uses up-conversion to cover the HF bands, it is possible that harmonics of the conversion oscillator are heterodyning UHF signals into the 20m band. This is ...
by g1hbe
Mon Jan 11, 2016 11:26 pm
Forum: SDR Antennas
Topic: Antenna input socket
Replies: 42
Views: 60603

Re: Antenna input socket

You could use a SMA to 259 or BNC adaptor lead. You can get them ready made with very flexible, thin coax which reduces the strain on the connector.
IMO there was not a lot wrong with the original F-connector!
by g1hbe
Sun Jan 10, 2016 11:00 pm
Forum: New Users' experiences
Topic: Using 2 LNAs for Inmarsat
Replies: 2
Views: 3791

Re: Using 2 LNAs for Inmarsat

I wonder if there is so much gain that out-of-band signals are overloading/blocking the receiver? Do you see a large increase in noise level when you put both amps in?
by g1hbe
Sun Jan 10, 2016 11:09 am
Forum: New Users' experiences
Topic: Learning to use SDRplay for Inmarsat
Replies: 12
Views: 18308

Re: Learning to use SDRplay for Inmarsat

So far I haven't even attempted any decoding, as my time is at a premium atm. I'm currently trying to rescue a water-logged loop antenna so I can get back on 160m.
by g1hbe
Sat Jan 09, 2016 4:24 pm
Forum: New Users' experiences
Topic: Learning to use SDRplay for Inmarsat
Replies: 12
Views: 18308

Re: Learning to use SDRplay for Inmarsat

Hi. Yup, bricks and mortar, over 100 years old and still standing. I tried the setup outside to see if the signals got any stronger, but from ground level (my radio shack is upstairs) the path is obstructed by more bricks and mortar (that's next door's house!).
by g1hbe
Sat Jan 09, 2016 10:56 am
Forum: New Users' experiences
Topic: Learning to use SDRplay for Inmarsat
Replies: 12
Views: 18308

Re: Learning to use SDRplay for Inmarsat

Scott, I've had similar experiences. I started with an active patch antenna and later moved to a home-made yagi with the patch as the driven element which worked great, but I noticed that the signals were always several dB stronger if I beamed through the brick wall instead of the window. I then rem...
by g1hbe
Thu Dec 17, 2015 9:22 am
Forum: SDRplay related
Topic: New features requests
Replies: 24
Views: 21109

Re: New features requests

I can't say I've noticed any particular weakness at 400 MHz. Mine shows a slight dip there (a few dB) but that may be my homebrew antenna diplexer. Of more concern is the oddness that starts around 255 MHz. I can't remember where it stops, but the RSP performs poorly in this area. It may be image re...
by g1hbe
Fri Nov 20, 2015 9:46 am
Forum: SDR Antennas
Topic: Magnetic Loop Antenna with SDRPlay
Replies: 9
Views: 19009

Re: Magnetic Loop Antenna with SDRPlay

Loops are a fantastic solution to local noise. I use the Wellbrook loop (ALA1530) and it has saved my bacon. Any attempt to use my vertical wire on RX just gives me S9 of noise on the lower bands, but the loop just ignores it. I can now operate on 160m again - vertical wire on TX, loop on RX. Bliss!
by g1hbe
Sun Nov 08, 2015 10:18 am
Forum: SDR Antennas
Topic: 50 ohm antenna connector on the SDRplay
Replies: 3
Views: 7589

Re: 50 ohm antenna connector on the SDRplay

It really doesn't matter either way. I'm not sure what the nominal input impedance of the SDR play is anyway, but it sure won't be constant over the bands. And the effect of the connector's impedance will be so tiny you can ignore it.
by g1hbe
Tue Oct 27, 2015 11:58 pm
Forum: General
Topic: Lowest frequency
Replies: 17
Views: 18608

Re: Lowest frequency

Hi Joerg. I find nothing beats my Wellbrook 1530 loop for S/N at low frequencies. All my wires and verticals return lots of local domestic noise here. Only the loop cuts through it. I find the Wellbrook works well down to about 40 KHz at least. It's mounted on a cheap rotator at gutter height. I'm n...