Search found 112 matches

by F1BJB
Thu Sep 03, 2015 6:11 pm
Forum: SDRplay related
Topic: SDRplay and MW/LF Reception
Replies: 7
Views: 7100

Re: SDRplay and MW/LF Reception

I have had mixed results I think it lacks an input filter.May be a front end attenuator too In fact my results are very good in daytime and very poor at night. It is certainly due to the fact that I'm using an 80m dipole with a ferrite balun that introduce a lot of loss in LW and MW. When SDR play ...
by F1BJB
Wed Sep 02, 2015 7:43 am
Forum: General
Topic: SDRPlay As Spectrum Analyzer
Replies: 3
Views: 3509

Re: SDRPlay As Spectrum Analyzer

Hi As any SDR receiver SDRplay acts a lot as a spectrum analyser. It mainly lacks: Absolute amplitude calibration Input attenuator shielding sweep frequency range tracking generator Depending on the software used, It is (often much) better for : cost sensitivity frequency calibration power consumpti...
by F1BJB
Wed Aug 19, 2015 9:37 pm
Forum: SDRplay related
Topic: I Q Supression
Replies: 2
Views: 2610

Re: I Q Supression

Stan wrote:If I'm using a rtl-usb stick it's a non issue.

Hi
This depends of the RTL stick.
With the R820 tuner it is not.
With the ET4000 it is a problem.
On the other hand ET4000 has less and more prédictable spurious responses as it is zero IF.
HTH
by F1BJB
Wed Aug 19, 2015 9:21 pm
Forum: SDRplay related
Topic: Broadcast FM duplicate image at +240mhz
Replies: 10
Views: 7549

Re: Broadcast FM duplicate image at +240mhz

Hi
As filter I had good results using a wall mounted TV/FM/SAT socket.
They are lowcost and easy to find .
My main problem was second order intermodulation products from the FM band falling in the DAB band.
I used an RTL dongle at the time.
HTH
by F1BJB
Mon Aug 17, 2015 9:56 pm
Forum: SDRplay related
Topic: SDRplay and MW/LF Reception
Replies: 7
Views: 7100

Re: SDRplay and MW/LF Reception

one of my tests for any radio is whether it can hear the weakish daytime signal from Manx Radio (1368 KHz) in the presence of the very strong signal from Asian Sound Radio (1377 KHz). Hi There is a trick that can help with SDR's in such a case: Tune the carrier of the strong signal at zero IF. Thus...
by F1BJB
Mon Aug 17, 2015 9:07 pm
Forum: General
Topic: Filters switching frequencies
Replies: 2
Views: 2356

Re: Filters switching frequencies

Many thanks for the quick answer and sorry for my late reaction.
by F1BJB
Sun Jul 19, 2015 10:58 am
Forum: General
Topic: F-connector or SMA - which is best?
Replies: 3
Views: 4109

Re: F-connector or SMA - which is best?

The main problem with F or SO239 connectors is continuity of the shielding. As SDRplay is using a plastic box this doesnt seems very important. Mine is wrapped in aluminium foil :P SMA has for me the advantage that my junk box is full of short professionnaly made cables. It simplifies connection to ...
by F1BJB
Fri Jul 17, 2015 8:23 am
Forum: General
Topic: Filters switching frequencies
Replies: 2
Views: 2356

Filters switching frequencies

Hi One of the things that decided my purchase was the nice documentation. Some details are missing. Am I right in assuming that 12 Mhz hardware frequency is the point where switching from the 0/12Mhz filter to the 12/30Mhz one happens ? This can be of importance : Imagine you want to receive 11.9Mhz...
by F1BJB
Thu Jul 16, 2015 5:21 pm
Forum: General
Topic: DRM audio codec - building - HELP!
Replies: 3
Views: 4057

Re: DRM audio codec - building - HELP!

With the last EXTIOsdrplay dll you can use SODIRA for DRM decoding.
PS :
Use as low as possible sampling frequency.
sodira was designed for soundcard input and is not good with high sampling rates.
by F1BJB
Thu Jul 16, 2015 1:32 pm
Forum: General
Topic: Removing Zero IF Image signals in FM Broadcast Band
Replies: 4
Views: 5924

Re: Removing Zero IF Image signals in FM Broadcast Band

Nice topic well illustrated.
In fact the FM Band here is so crowded that image was never a problem :)
One thing worth saying is that another way of solving the problem is to change the center tuning frequency.
and thus the offset of the desired station.

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