Date   

Re: 137MHz "V" Antenna advice needed ...

Kriss Kliegle KA1GJU
 

Slightly confused... any images of said 8 element horizontal V dipole?
With that said...
A beam (Yagi) with 8 elements will be highly directional, not something you want when chasing a satellite that is moving across the sky... unless you plan on using an azimuth/elevation rotator (more complexity).
I know one satellite operator in the club uses the 'egg beater' type antennas, they're omnidirectional  and no there are no moving parts to fail.

Typically in a beam antenna, the elements are +/- 1/2 wave long (two +/- 1/4 wave elements connected together to form one +/- 1/2 wavelength long element). Since the center of each parasitic element (essentially a dipole) is at 0 volts, the element is usually clamped to a metal boom without being insulated.
Lots of info on the web to get dimensions of each element and the spacing (google "VHF beam antenna dimensions" or similar)

i.e: https://www.rfwireless-world.com/calculators/3-element-Yagi-Antenna-Calculator.html
Yagi Antenna calculator Formula
Yagi beam antennas are great for narrowing the 'field of view' of RF, but once not aimed within the beam width, the RX'ed signal can drop off dramatically.
Antenna specs of commercially available antennas will state what the half-power beam width is. For example a -3dB drop or half power drop from the main lobe:

Antenna Beamwidth

The more elements added, the more forward gain (better front to back ratio)... at a cost of a more narrow beam width. Of course there are lots of variables that can be tweaked, height above ground, element spacing, element lengths, etc to change the specs of a beam.

Confused yet?

73 Kriss KA1GJU/AM


137MHz "V" Antenna advice needed ...

David Slipper
 

Hi, I am in the process of making a "horizontal 'V' dipole" antenna for receiving NOAA and have a question about adding a reflector.

It will have 8 elements in the reflector and my questions are :-

1. Do the 8 elements need to be connected to each other ???

2. Does the reflector need to be grounded ??? or perhaps connected to the coax braid in some way ???

I'm a newbie in all this so any advice is welcome.

Regards,
Dave


Re: A new way to shut off a PC

Robin Francis
 

That is exactly what was happening to me  6 months ago. A new uprated PSU fixed it.

Robin ZL1RNF

 

Sent from Mail for Windows

 


Re: A new way to shut off a PC

Dennis Matzen
 

I would also suspect the power supply. It could be that when you start SDR Console the increased load on the power supply (both for the USB attached SDR as well as the graphics card) is causing the power supply to kick off. It may be rated high enough to support the system but with age it may not be able to deliver that load any more. This would explain why there are no logs indicating why it shutdown. The system just stops before any logs can be written to. But you should see in the event log an entry that the system had an unexpected shutdown. Same thing is if the power cable was pulled.
--
Dennis
KA6FUB


Re: A new way to shut off a PC

michel soldevila
 

I have 3 disks in my PC : one 500 GB SSD for the system, and two 3 TB HDD for the data (mostly pictures RAW files). All are monitored by CrystalDiskInfo, which does not report any problem.
Again, Speccy returns normal operating temperatures: 40 ° C for the discs, 58°C for the graphic card,  25°C inside the PC box. Dust has been removed, all 3 fans checked (main fan, CPU fan, graphic processor fan). 
I will open the PC again to add thermal paste on the CPU.

@G3PIY : Windows 10 was installed on the SSD after formating it. All other programs were installed after.
Michel, F1GOC


Re: A new way to shut off a PC

Allan Isaacs
 

Same here Nick.

I had lots of intermittent problems lately and found disk errors marked in the system logs corresponding timewise to the problems.

The pair of 525GB SSDs in RAID carried on regardless being quite resilient.

I bought a pair of 1TB SSDs onto which I cloned the old drives and touch wood no problems since.

 

Any graphics card using a fan should be detached regularly and the fan bearing oiled as they can run slow due to a build up of dust.

Peel back the centre sticker and lubricate the end of the spindle.

Allan G3PIY


From: main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of Nick Arend via groups.io
Sent: 21 December 2021 14:40
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] A new way to shut off a PC

 

Definitely check the SMART info for your disks: https://www.howtogeek.com/134735/how-to-see-if-your-hard-drive-is-dying/

It wouldn't hurt. I had a failing drive one time and it manifested all sorts of strange and seemingly unrelated problems. One was that it would crash an Nvidia driver every time I did anything GPU intensive. Once I discovered the bad drive and unplugged it, I no longer had problems.

_._,_._,_

 


Re: A new way to shut off a PC

Nick Arend
 

Definitely check the SMART info for your disks: https://www.howtogeek.com/134735/how-to-see-if-your-hard-drive-is-dying/

It wouldn't hurt. I had a failing drive one time and it manifested all sorts of strange and seemingly unrelated problems. One was that it would crash an Nvidia driver every time I did anything GPU intensive. Once I discovered the bad drive and unplugged it, I no longer had problems.


Re: A new way to shut off a PC

David De Coons
 

I have also seen fans on graphic cards fail without any user warning. Could also be an accumulation of dust slowing things down. 

My case has screens on air intakes that catch 99% of dust before it enters the PC. The screens pop out for easy rinse under the water faucet. 

Dave wo2x

Sent from my waxed string and tin cans. 

On Dec 21, 2021, at 10:19 AM, Allan Isaacs <allan@...> wrote:



When you installed Windows 10 did you switch off all the intrusive programs?

These are turned off in the non-express install or whatever they call it.

If you failed to turn these off the processor load may be a lot higher than with your Win 7 installation hence aggravating overheating?

As Simon suggested the processor heatsink paste may need renewing if your heatsink looks clean and your fan is running OK.

The graphics chip might be running too hot. Does it have a fan or is it a silent type?

Allan G3PIY


From: main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of michel soldevila
Sent: 21 December 2021 15:07
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] A new way to shut off a PC

 

The disks are in good conditions according to CrystalDiskInfo. The resync only happens when the PC suffers an unexpected shutdown. As pointed out by Allan, this is normal opération.

Come to think of it, this problem arose quite recently (before switching from Windows 7 to  Windows 10) and has evolved rapidly. Initially, the PC did not stop with each launch of SDR Console, as is the case today.
This could favor the thermal failure hypothesis. However, Speccy returns normal temperatures: 40 ° C for the discs, 58°C for the graphic card,  25°C inside the PC box.

Fortunately, I have my laptop to continue listening to shortwave while investigating this issue!
Michel, F1GOC


Re: A new way to shut off a PC

Allan Isaacs
 

When you installed Windows 10 did you switch off all the intrusive programs?

These are turned off in the non-express install or whatever they call it.

If you failed to turn these off the processor load may be a lot higher than with your Win 7 installation hence aggravating overheating?

As Simon suggested the processor heatsink paste may need renewing if your heatsink looks clean and your fan is running OK.

The graphics chip might be running too hot. Does it have a fan or is it a silent type?

Allan G3PIY


From: main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of michel soldevila
Sent: 21 December 2021 15:07
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] A new way to shut off a PC

 

The disks are in good conditions according to CrystalDiskInfo. The resync only happens when the PC suffers an unexpected shutdown. As pointed out by Allan, this is normal opération.

Come to think of it, this problem arose quite recently (before switching from Windows 7 to  Windows 10) and has evolved rapidly. Initially, the PC did not stop with each launch of SDR Console, as is the case today.
This could favor the thermal failure hypothesis. However, Speccy returns normal temperatures: 40 ° C for the discs, 58°C for the graphic card,  25°C inside the PC box.

Fortunately, I have my laptop to continue listening to shortwave while investigating this issue!
Michel, F1GOC

_._,_._,_

 


Re: A new way to shut off a PC

michel soldevila
 

The disks are in good conditions according to CrystalDiskInfo. The resync only happens when the PC suffers an unexpected shutdown. As pointed out by Allan, this is normal opération.

Come to think of it, this problem arose quite recently (before switching from Windows 7 to  Windows 10) and has evolved rapidly. Initially, the PC did not stop with each launch of SDR Console, as is the case today.
This could favor the thermal failure hypothesis. However, Speccy returns normal temperatures: 40 ° C for the discs, 58°C for the graphic card,  25°C inside the PC box.
Fortunately, I have my laptop to continue listening to shortwave while investigating this issue!
Michel, F1GOC


Re: Airspy Black Friday Sales event is ON! 😍

jdow
 

Not to my knowledge.
{^_^}

On 20211221 03:39:50, David J Taylor via groups.io wrote:

On 21/12/2021 11:18, jdow wrote:
Here is the best link with pictures:
https://groups.io/g/airspy/message/26592

Thanks, Joanne.

I knew bout the mod for the HF+, but I /thought/ that someone had done similar with the HF+ Discovery.  Likely I'm mistaken!

73,
David GM8ARV


Re: A new way to shut off a PC

Allan Isaacs
 

Any unexpected shutdown will result in that hard drive resync especially if its Windows software RAID.

 

If it’s a bad disk you’ll always get red marks in the System log.

If the PC goes to a black screen and then the PC is manually powered off and rebooted the System log will just show an unexpected error without pinning down the cause. Then the RAID will resync. Could the problem perhaps be insufficient USB current to power the SDR?

 

If it was a programmed shutdown no resync would be initiated so I agree we’re back to a hardware fault.

Another way to check is to read the hard drive Smart data and see if one shows lots of errors.

Allan G3PIY


From: main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of Simon Brown
Sent: 21 December 2021 13:39
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] A new way to shut off a PC

 

You’ve got a bad disk or bad disk controller.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of michel soldevila
Sent: 21 December 2021 13:02
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] A new way to shut off a PC

 

No BSOD. Black screen, power off. And 3 Tb RAID 1 HDD re-synchronisation after power on :-(




Re: Airspy Black Friday Sales event is ON! 😍

Max
 

On Tue, Dec 21, 2021 at 12:03 PM, Alan G4ZFQ wrote:
Yes, the Discovery is different and works well at all frequencies without any modification. Probably not possible anyway.

I'm surprised Max is disappointed, I'd expect it to be difficult to notice any difference between good receivers on HF.

Should have said, yes it of course is the Discovery, not the older HF+ version.

Re. disappointed, yes I was very surprised indeed that there was such an audible difference between them, but it was very clear. To be fair we are talking about a signal right on the edge of the noise, but that's where it matters most apparently. And yes, I did try tweaking all available settings in the HF+ (Discovery). I should have made a recording to show the difference.

I don't think it is in anyway an indicator of any issues with the Discovery, just was so surprised at how truly excellent the Hermes Lite was. Signal really was plain as day with the HL2 (and no fiddling with any settings either as there is only one - LNA gain, at that I don't need to move anyway). It just worked immediately. But also it was at a frequency where we were told by the designer that the "stock" performance is rolling off because really it's an HF amateur bands transceiver, not an LF or VLF so much. But seems it's great at LF too.

Will report back after Grimeton (24th but also two test transmission on 23rd December) on 17.2 kHz. Will be very interesting to see any difference there between the two.

So far just confirms that Hermes Lite 2 is the bargain of the century (so far) at around £200 GBP for a fully fledged SDR direct sampling HF transceiver!

Max


Re: A new way to shut off a PC

Simon Brown
 

You’ve got a bad disk or bad disk controller.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of michel soldevila
Sent: 21 December 2021 13:02
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] A new way to shut off a PC

 

No BSOD. Black screen, power off. And 3 Tb RAID 1 HDD re-synchronisation after power on :-(


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Re: A new way to shut off a PC

michel soldevila
 

No BSOD. Black screen, power off. And 3 Tb RAID 1 HDD re-synchronisation after power on :-(


Re: Airspy Black Friday Sales event is ON! 😍

Alan G4ZFQ
 

I knew bout the mod for the HF+, but I /thought/ that someone had done similar with the HF+ Discovery.  Likely I'm mistaken!
David

Yes, the Discovery is different and works well at all frequencies without any modification. Probably not possible anyway.

I'm surprised Max is disappointed, I'd expect it to be difficult to notice any difference between good receivers on HF.

73 Alan G4ZFQ


Re: Airspy Black Friday Sales event is ON! 😍

David J Taylor
 

On 21/12/2021 11:18, jdow wrote:
Here is the best link with pictures:
https://groups.io/g/airspy/message/26592
Thanks, Joanne.

I knew bout the mod for the HF+, but I /thought/ that someone had done similar with the HF+ Discovery. Likely I'm mistaken!

73,
David GM8ARV
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv


Re: Airspy Black Friday Sales event is ON! 😍

jdow
 

Here is the best link with pictures:
https://groups.io/g/airspy/message/26592

{^_^}

On 20211221 03:03:36, David J Taylor via groups.io wrote:

On 21/12/2021 00:21, Max wrote:
Big surprise trawling around NDBs, CHT Chiltern CW ident audible with total clarity (admittedly only couple dB off noise level) on Hermes Lite 2. Just detectable but only intermittently readable with difficulty on HF+. I guess that just confirms what a superb receiver the Hermes Lite is (as I actually already suspected). Bit disappointed in the HF+. Expected it to significantly better the HL2 at that frequency.

Be very interested to hear comparison when Grimeton powers up on 24th December on 17.2 kHz @ 07.30 UTC. Seems they will now be on air after all having previously said they would not.

Let's see if HF+ proves its worth then!

Max

I have seen suggestions that increasing one capacitor (or whatever) can improve the LF and VLF performance, but I don't recall where, or whether this recommended!  Perhaps ask here?

  https://groups.io/g/airspy

Cheers,
David


Re: Airspy Black Friday Sales event is ON! 😍

jdow
 

Duck Duck Go is your friend. Search for '"airspy hf+" capacitor fix' without the single quotes. About the fourth citation is a groups.io posting with what you want.

{^_^}

On 20211221 03:03:36, David J Taylor via groups.io wrote:

On 21/12/2021 00:21, Max wrote:
Big surprise trawling around NDBs, CHT Chiltern CW ident audible with total clarity (admittedly only couple dB off noise level) on Hermes Lite 2. Just detectable but only intermittently readable with difficulty on HF+. I guess that just confirms what a superb receiver the Hermes Lite is (as I actually already suspected). Bit disappointed in the HF+. Expected it to significantly better the HL2 at that frequency.

Be very interested to hear comparison when Grimeton powers up on 24th December on 17.2 kHz @ 07.30 UTC. Seems they will now be on air after all having previously said they would not.

Let's see if HF+ proves its worth then!

Max

I have seen suggestions that increasing one capacitor (or whatever) can improve the LF and VLF performance, but I don't recall where, or whether this recommended!  Perhaps ask here?

  https://groups.io/g/airspy

Cheers,
David


Re: Airspy Black Friday Sales event is ON! 😍

David J Taylor
 

On 21/12/2021 00:21, Max wrote:
Big surprise trawling around NDBs, CHT Chiltern CW ident audible with total clarity (admittedly only couple dB off noise level) on Hermes Lite 2. Just detectable but only intermittently readable with difficulty on HF+. I guess that just confirms what a superb receiver the Hermes Lite is (as I actually already suspected). Bit disappointed in the HF+. Expected it to significantly better the HL2 at that frequency.
Be very interested to hear comparison when Grimeton powers up on 24th December on 17.2 kHz @ 07.30 UTC. Seems they will now be on air after all having previously said they would not.
Let's see if HF+ proves its worth then!
Max
I have seen suggestions that increasing one capacitor (or whatever) can improve the LF and VLF performance, but I don't recall where, or whether this recommended! Perhaps ask here?

https://groups.io/g/airspy

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv

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