Date   
Re: W10 Update - MPX Output, RDS spy, Virtual Cables and UAC

Patrick
 

Decoding is also OK when running a Spyserver ...

Re: W10 Update - MPX Output, RDS spy, Virtual Cables and UAC

Patrick
 

Because a pic probably explains better ...

W10 Update - MPX Output, RDS spy, Virtual Cables and UAC

Patrick
 

Hi there !

Yesterday, after W10 April update (v1803), I noticed that both RDS spy (via MPX Output plugin) and DSD+ did not work.

Here is the explanation a kind guy sent me : in Win 10 1803 Build 17134.1, Microsoft have made a significant (undocumented) change in sound card handling with the April Update.
You will now need to select PC Settings -> *PRIVACY* -> Microphone and *TURN ON* "Allow apps to access your microphone".
The "Allow apps to access your microphone" now means "Allow apps to use sound devices for input". If "Allow apps to access your microphone" is turned off, Windows will not pass audio to *any* application.

I applied the trick and DSD+ immediatly worked. So it looks like the virtual cables are OK (VB cables)

But the problem remains when running RDSspy for LIVE LISTENING only. Decoding is 100% OK when playing a file.
It seems the culprit is the MPX Output (ticking / unticking, setting its level from min to max has no effect on the 'Peak Input signal level' in RDS spy (its shows 'silence').
As said before, if using exactly the same settings, everything is OK when playing a recorded file.

Any idea ?
(please use simple words, my english being limited when it comes to technical purpose)

Thanks a lot

Re: Airspy R2 LDO blown

Martin Smith
 

There is a PPTC for the Bias-T ( https://en.wikipedia.org/wiki/Resettable_fuse ) on the Airspy NOS R0 and Airspy NOS R2. I think it is marked as FB2 on the PCB, but I could be wrong (see bottom left of pin assignment images http://www.pe0sat.vgnet.nl/sdr/receivers/airspy/ )

The PPTC will protect against short duration accidental current overload (or shorting out) of the Bias-T. But it is still best to avoid tripping the PPTC. According to wikipedia it can take minutes/hours/days/weeks/months to recover from overloading a PPTC long enough. I'd be inclined to unplug it for a week and see if the the PPTC regenerates.

Re: Airspy R2 LDO blown

Laurie
 

On 12/05/2018 10:30, jdow wrote:
On 20180512 02:12, Laurie wrote:
Digikey?

https://www.digikey.co.uk/product-detail/en/texas-instruments/LP5907MFX-4.5-NOPB/296-39064-1-ND/5143093
Minimum order?
Minimum order is 1 but they do charge £12 shipping for orders under £50.

Laurie

--

Re: Airspy R2 LDO blown

jdow
 

On 20180512 02:12, Laurie wrote:
On 11/05/2018 20:58, Terry Gaff wrote:
Has anybody ever had the bias-T LDO device (LP5907MFX-4.5/NOPB) in an Airspy R2 meet it's maker and replace it ? My own one has blown somehow and I need to replace it. I can do this myself but wondering of any recommendations of where to get a couple in europe without costing an arm and a leg...
Digikey?
https://www.digikey.co.uk/product-detail/en/texas-instruments/LP5907MFX-4.5-NOPB/296-39064-1-ND/5143093
Minimum order?
{^_^}

Re: Airspy R2 LDO blown

Laurie
 

On 11/05/2018 20:58, Terry Gaff wrote:
Has anybody ever had the bias-T LDO device (LP5907MFX-4.5/NOPB) in an Airspy R2 meet it's maker and replace it ? My own one has blown somehow and I need to replace it. I can do this myself but wondering of any recommendations of where to get a couple in europe without costing an arm and a leg...
Digikey?

https://www.digikey.co.uk/product-detail/en/texas-instruments/LP5907MFX-4.5-NOPB/296-39064-1-ND/5143093

Laurie
--

Airspy R2 LDO blown

Terry Gaff
 

Hi all,
Has anybody ever had the bias-T LDO device (LP5907MFX-4.5/NOPB) in an Airspy R2 meet it's maker and replace it ? My own one has blown somehow and I need to replace it. I can do this myself but wondering of any recommendations of where to get a couple in europe without costing an arm and a leg... otherwise it's the peoples republic and up to an 8 week wait.
Many thanks.
Terry

AstroSpy - automatic csv logging #radioastronomy

Jochen Richert
 

Dear Developers
Long ago we requested the feature for data logging out of AstroSpy and we received the answer, that all the development power was focused on the release of the HF+. Because the HF+ is now out and running, I would like to bring up the question again.
Is it possible to extend AstroSpy for a periodically logging of the data into a csv or other kind of file?

Many thanks for your support
HB9DRT, Joe

locked Re: VLF Reception

prog
 

On Fri, May 11, 2018 at 06:16 am, Maurizio Marini wrote:
I would like to understand if it is more correct to put the 4.7 nF coupling cap on R3.
As I said in my previous message: DO NOT change anything if you are not involved in designing RF front ends and know exactly what you are doing.
You will get better results if you avoid falling in the "not suitable" cases in that matrix - which means: Use the right antenna for the right band.

PS: The purpose of these public forums is not to educate people on how to design radios. It's an easy way for the designers to tell people how they should use the product. Ignoring the recommendations ALWAYS end up with a mess.

locked Re: VLF Reception

Maurizio Marini
 

Hi Prog,

the 4.7 nF coupling cap is the new value of R3?
How do we understand if our AirspyHF + already has this change?
From the S / N?
(My s / n is 36529480D5343F93)

I use my own active loop and mini-whip on the MW and I currently shorted r3.
I would like to understand if it is more correct to put the 4.7 nF coupling cap on R3.

My interest in LW/MW.



Thank you,


Maurizio IW2GOB




Il 11/05/2018 12:47, prog ha scritto:
On Fri, May 11, 2018 at 03:35 am, Alan G4ZFQ wrote:
The only reception I get is on my discone, so I'd suggest anyone tries any "stupid" antenna they have.
Not uncommon. Good HF antennas are in general poor in the VLF band. In the other hand, the NF of the HF+ is so low that a small whip would work just fine and without modding anything. Just make sure you are not contaminating your antenna with your own noise. Leif posted a series of videos about this topic, so I invite everybody to check his YouTube channel: https://www.youtube.com/channel/UClmNy6VRE1YqOeBHwb3o0Yg/videos

FYI. The newer HF+ batches have a 4.7 nF coupling cap in the HF path and the RF front-end was programmed accordingly. This helps getting a better impedance matching with some antennas like the active loops/mini whips. Other antennas should work the same.

locked Re: VLF Reception

Chris Wilson
 

Hello Alan,

I sometimes use Martin G8JNJ's web based SDR which is a KiwiSDR. If
you go on his site you need to select "Antenna 5" which is a monopole.
I haven't looked at what it's like at VLF, but it's pretty keen on 136
Hz, and trying it costs nowt :) His web site has a lot of info on LF
and VLF antennas. Please be sure to reset the WebSDR to antenna 1 when
leaving, as the monopole is not much good on HF!

http://southwest.ddns.net:8073/?ext=ant_switch

I have not had much luck with an active mini whip on LF (136khz) so
use my resonant TX aerial for RX, into a Red Pitaya with input mods.
It seems to hear as well as most good UK set ups. What a well sited
mini whip is like on VLF I don't know, some swear by them, some swear
at them :)

Regards, 2E0ILY

Friday, May 11, 2018

Anyone wanting to test their VLF reception can now do so at the bottom
end of HF+ range again, as the Russian Alpha navigation signals are now
back on air after a near four month shutdown.  The 11.90, 12.65 and
14.88kHz signals are coming in well in the UK at the moment.
Dave,
Thanks, I'd almost given up looking.
My HF+ does have the R3 mod. The only reception I get is on my discone,
so I'd suggest anyone tries any "stupid" antenna they have.
(I've also tried my Wellbrook, various wires, dipoles, e-probes,
vertical to simulate the discone's situation and receive nothing there.)
The discone also did very well on SAQ hearing the carrier leakage before
they started keying. Surely I can make something better...
73 Alan G4ZFQ
--
Best regards,
Chris mailto:chris@...

locked Re: VLF Reception

prog
 

On Fri, May 11, 2018 at 04:40 am, D R wrote:
Hi prog - would you recommend the 4.7nF cap in place of the short across R3 which I've had in place since early January, or would it not make much difference?  The short works very well with my loops, but every little extra is welcome.
 
Regards,
Dave
It depends. The general recommendation is: Do not change anything unless you know what you are doing.
So, I will suppose you already know how the front end filtering, impedance matching and the different AGC loops all act in concert to optimize your reception. Here's a table to summarize the ideal coupling depending on the (most common) scenarios:

Target band Small whip HF Resonnant Dipole Active Loop Active Mini Whip
VLF 300 pF - Not suitable - - Not suitable - 4.7 nF
LW/MW (AM BC) 300 pF 4.7 nF 10 nF 4.7 nF
Shortwaves / HAM 300 pF 300 pF 4.7 nF 4.7 nF

The cells marked as "not suitable" simply mean that the antenna will just "eat" the available dynamic range of the radio without improving the performance in the target band.

locked Re: VLF Reception

D R
 

Hi prog - would you recommend the 4.7nF cap in place of the short across R3 which I've had in place since early January, or would it not make much difference?  The short works very well with my loops, but every little extra is welcome.

Regards,
Dave


On Friday, 11 May 2018, 11:47:25 GMT+1, prog <info@...> wrote:


On Fri, May 11, 2018 at 03:35 am, Alan G4ZFQ wrote:
The only reception I get is on my discone, so I'd suggest anyone tries any "stupid" antenna they have.
Not uncommon. Good HF antennas are in general poor in the VLF band. In the other hand, the NF of the HF+ is so low that a small whip would work just fine and without modding anything. Just make sure you are not contaminating your antenna with your own noise. Leif posted a series of videos about this topic, so I invite everybody to check his YouTube channel: https://www.youtube.com/channel/UClmNy6VRE1YqOeBHwb3o0Yg/videos

FYI. The newer HF+ batches have a 4.7 nF coupling cap in the HF path and the RF front-end was programmed accordingly. This helps getting a better impedance matching with some antennas like the active loops/mini whips. Other antennas should work the same.

locked Re: VLF Reception

D R
 

Hi Alan,

You were hearing Krasnodar and the double pulse from Novosibirsk in that recording.  Here's what they looked like on my HF+ and Wellbrook LFL1010 loop.

Regards,
Dave


On Friday, 11 May 2018, 11:35:13 GMT+1, Alan G4ZFQ <alan4alan@...> wrote:


> Anyone wanting to test their VLF reception can now do so at the bottom
> end of HF+ range again, as the Russian Alpha navigation signals are now
> back on air after a near four month shutdown.  The 11.90, 12.65 and
> 14.88kHz signals are coming in well in the UK at the moment.

Dave,

Thanks, I'd almost given up looking.
My HF+ does have the R3 mod. The only reception I get is on my discone,
so I'd suggest anyone tries any "stupid" antenna they have.
(I've also tried my Wellbrook, various wires, dipoles, e-probes,
vertical to simulate the discone's situation and receive nothing there.)
The discone also did very well on SAQ hearing the carrier leakage before
they started keying. Surely I can make something better...

73 Alan G4ZFQ




locked Re: VLF Reception

prog
 

On Fri, May 11, 2018 at 03:35 am, Alan G4ZFQ wrote:
The only reception I get is on my discone, so I'd suggest anyone tries any "stupid" antenna they have.
Not uncommon. Good HF antennas are in general poor in the VLF band. In the other hand, the NF of the HF+ is so low that a small whip would work just fine and without modding anything. Just make sure you are not contaminating your antenna with your own noise. Leif posted a series of videos about this topic, so I invite everybody to check his YouTube channel: https://www.youtube.com/channel/UClmNy6VRE1YqOeBHwb3o0Yg/videos

FYI. The newer HF+ batches have a 4.7 nF coupling cap in the HF path and the RF front-end was programmed accordingly. This helps getting a better impedance matching with some antennas like the active loops/mini whips. Other antennas should work the same.

locked Re: VLF Reception

Alan G4ZFQ
 

Anyone wanting to test their VLF reception can now do so at the bottom end of HF+ range again, as the Russian Alpha navigation signals are now back on air after a near four month shutdown.  The 11.90, 12.65 and 14.88kHz signals are coming in well in the UK at the moment.
Dave,

Thanks, I'd almost given up looking.
My HF+ does have the R3 mod. The only reception I get is on my discone, so I'd suggest anyone tries any "stupid" antenna they have.
(I've also tried my Wellbrook, various wires, dipoles, e-probes, vertical to simulate the discone's situation and receive nothing there.)
The discone also did very well on SAQ hearing the carrier leakage before they started keying. Surely I can make something better...

73 Alan G4ZFQ

locked Re: VLF Reception

Dana Myers
 

On 5/10/2018 11:37 AM, D R via Groups.Io wrote:
Anyone wanting to test their VLF reception can now do so at the bottom end of HF+ range again, as the Russian Alpha navigation signals are now back on air after a near four month shutdown.  The 11.90, 12.65 and 14.88kHz signals are coming in well in the UK at the moment.
Several months ago, I cobbled-together an e-probe antenna and had good
results with VLF reception here in California. I did the 'R3' mod (100nF cap
piggybacked).

Recently, on a whim I connected my 25-1300MHz discone antenna to the HF
port. Without doing an A/B comparison, I can't say for sure, but I think it
works essentially as well as the e-probe did (and is less prone to overload).

I'll take a listen for the Russian Alpha stations this evening.

Cheers,
Dana

locked VLF Reception

D R
 

Anyone wanting to test their VLF reception can now do so at the bottom end of HF+ range again, as the Russian Alpha navigation signals are now back on air after a near four month shutdown.  The 11.90, 12.65 and 14.88kHz signals are coming in well in the UK at the moment.

Regards,
Dave

Re: Recording baseband and audio in #sdrsharp

chutton12000
 

t doesn't need to get so complicated.
SDRs like the Perseus or RF Space units create 2 GB files and then keep recording seamlessly in a new file when 2 GB is reached.
No need to go off into the world of specialized formats.

Chuck