Date   

GB3KBQ

John Fell
 

1416 -12 1.1 833 $* GB3KBQ IO80LX


73

John

G0API


Re: GB3OSW

John Fell
 

Hi Peter,
Thanks for doing the work - what was involved ?
Still looking for the first decode down here over the mountains ....
73
John
G0API

On Fri, 5 Mar 2021 at 12:52, Peter G3SMT via groups.io <peter.torry=talktalk.net@groups.io> wrote:

Martyn,

Thanks for the report. I was going to leave it a few days to ensure all was well before announcing its return and apologising for the length of time it was off the air but I will update beaconspot today.

73 

Peter   G3SMT


On 05/03/2021 12:33, Martyn G3UKV wrote:
Welcome back beacon GB3OSW (IO82KV80) on 3cm - 10368.780 MHz.
Not many spotters so far on beaconspot.uk - so have a listen if possible.
Thanks Peter (G3SMT - beacon NoV).
73 Martyn G3UKV

Virus-free. www.avg.com

--
Peter G3SMT


Re: Nano VNA SAA-2N and G3XDY QRO filter

geoffrey pike
 

The only snag is the time to sweep a filter and with the software i use i see no continuous sweep facility like
the NanoVNA has, but yes good value and very easy to use especially the calibration
 Geoff
GI0GDP

On Friday, 5 March 2021, 11:25:22 GMT, david656179 via groups.io <david.m.k@...> wrote:


Just finished the 2nd filter, these 0603 components are tricky and can fly long distances !!

Note to say that by setting different calibrated ranges for 1296 - 2592 and 3888 MHz on this VNA I was able to check the return loss at 1296 and tune for best dips at 2592 and 3888.  The point being that the VNA is listed as 3 GHz top frequency, mine appeared to go to 4 GHz.  Sure the readings might be inaccurate but if one is just tuning a filter for rejection, finding this extended range was a pleasant surprise.  I have not altered any of the firmware/software from purchase last Autumn, when I think i am right is saying John XDY, reported that there were several owners in the Ipswich area.  A remarkable unit for around £100 carriage paid.

David


Re: attenuator

Alan Melia
 


Hi Ben here isa calculator of what it should read usinga DMM from the files area of the Group
 
 
Alan
G3NYK

----- Original Message -----
Sent: Friday, March 05, 2021 12:01 PM
Subject: [UKMicrowaves] attenuator

I have this 100W 30db attenuator but the i/p measures 14 ohms to gnd, the o/p 51 ohm to gnd and the through is 61 ohm. 

I'm thinking its duff? 

Ben
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Re: attenuator

militaryoperator
 

Ben,
 
Mine measures 50ohm in and out to ground and 92ohm through (inner to inner)
 
Hope this helps
 
Colin de G8LBS.
 

Yes, other ones here are similar. I think I have a nice heatsink!

Ben


Re: Nano VNA SAA-2N and G3XDY QRO filter

Colin Ranson
 

Yes, I have one that John set up for me, its a work of art !

 

De G8LBS, Ipswich.

 

Sent from Mail for Windows 10

 

From: david656179 via groups.io
Sent: 05 March 2021 11:25
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Nano VNA SAA-2N and G3XDY QRO filter

 

Just finished the 2nd filter, these 0603 components are tricky and can fly long distances !!

Note to say that by setting different calibrated ranges for 1296 - 2592 and 3888 MHz on this VNA I was able to check the return loss at 1296 and tune for best dips at 2592 and 3888.  The point being that the VNA is listed as 3 GHz top frequency, mine appeared to go to 4 GHz.  Sure the readings might be inaccurate but if one is just tuning a filter for rejection, finding this extended range was a pleasant surprise.  I have not altered any of the firmware/software from purchase last Autumn, when I think i am right is saying John XDY, reported that there were several owners in the Ipswich area.  A remarkable unit for around £100 carriage paid.

David

 


Re: GB3OSW

Peter G3SMT
 

Martyn,

Thanks for the report. I was going to leave it a few days to ensure all was well before announcing its return and apologising for the length of time it was off the air but I will update beaconspot today.

73 

Peter   G3SMT


On 05/03/2021 12:33, Martyn G3UKV wrote:
Welcome back beacon GB3OSW (IO82KV80) on 3cm - 10368.780 MHz.
Not many spotters so far on beaconspot.uk - so have a listen if possible.
Thanks Peter (G3SMT - beacon NoV).
73 Martyn G3UKV

Virus-free. www.avg.com

--
Peter G3SMT


Re: attenuator

Colin Ranson
 

Ben,

 

Mine measures 50ohm in and out to ground and 92ohm through (inner to inner)

 

Hope this helps

 

Colin de G8LBS.

 

 

Sent from Mail for Windows 10

 

From: militaryoperator via groups.io
Sent: 05 March 2021 12:01
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] attenuator

 

I have this 100W 30db attenuator but the i/p measures 14 ohms to gnd, the o/p 51 ohm to gnd and the through is 61 ohm. 

 

I'm thinking its duff? 

 

Ben

 


Re: attenuator

Gordon REASON <gordonj.reason@...>
 

Looking at an online attenuator calculator , for a Pi style , fo 50 Ohms .........                                                         some 52 ohms to ground at each end , and 789 ohms across the top ...........

So , a choice ......... it's either been fried ........ or the label has been changed .........

Do you have a Vna , to check it with ?

On 05 March 2021 at 12:01 "militaryoperator via groups.io" <Military1944@...> wrote:

I have this 100W 30db attenuator but the i/p measures 14 ohms to gnd, the o/p 51 ohm to gnd and the through is 61 ohm. 

I'm thinking its duff? 

Ben


GB3OSW

Martyn G3UKV
 

Welcome back beacon GB3OSW (IO82KV80) on 3cm - 10368.780 MHz.
Not many spotters so far on beaconspot.uk - so have a listen if possible.
Thanks Peter (G3SMT - beacon NoV).
73 Martyn G3UKV

Virus-free. www.avg.com


attenuator

militaryoperator
 

I have this 100W 30db attenuator but the i/p measures 14 ohms to gnd, the o/p 51 ohm to gnd and the through is 61 ohm. 

I'm thinking its duff? 

Ben


Nano VNA SAA-2N and G3XDY QRO filter

david656179
 

Just finished the 2nd filter, these 0603 components are tricky and can fly long distances !!

Note to say that by setting different calibrated ranges for 1296 - 2592 and 3888 MHz on this VNA I was able to check the return loss at 1296 and tune for best dips at 2592 and 3888.  The point being that the VNA is listed as 3 GHz top frequency, mine appeared to go to 4 GHz.  Sure the readings might be inaccurate but if one is just tuning a filter for rejection, finding this extended range was a pleasant surprise.  I have not altered any of the firmware/software from purchase last Autumn, when I think i am right is saying John XDY, reported that there were several owners in the Ipswich area.  A remarkable unit for around £100 carriage paid.

David


Re: GB3MCB current frequency?

John Fell
 

Hi Neil,
GB3MCB is specified to use F1A keying .It does not have any digital add ons .

I do not think Brian G4NNS added any external locking to the LO , so periodic drift is probable .

I had a sniff from it in January this year , very short duration .At that time it was 10368.9685MHz - BeaconSpot lists a few other spots within 2 kHz of that area .

When I was last in GW , in Pembrokeshire 2019, it was a strong signal along the coast and its keying and short term stability  good .
In this direction (E) it has to get over the mass of Dartmoor , so I do not expect to hear it much , even though I had my West end Pine tree topped last week. .
I do not bother elevating my telescopic mast much but did in January "coz it felt right" kind of Tropogation - something that is in limited supply at the moment .
I have seen FNY more often !

With KBQ , CAM , RPE and effectively MHZ all QRT ,we could do with more Beacon sources on 10GHz .

What's occurring Chaps ?

73
John
G0API

On Thu, 4 Mar 2021 at 22:15, Neil Smith G4DBN <neil@...> wrote:

I'm seeing a very very weak trace on 10368.97056 MHz coming from the right direction to be GB3MCB. It is a little bit wobbly, by up to 10 Hz. It disappears when I beam away or elevate, but I don't see any obvious FSK.  I seem to remember that MCB used to have a very very narrow shift, and tended to bounce a bit during the keying cycles, but it is so long since I heard it last that I might be seeing something totally different.  Just seems concidence that the signal is in the right direction, and somewhere near the right frequency.  MCB is 460 km away, so no wonder it's weak, but this doesn't feel quite right.  Can anyone confirm what frequency MCB is on right now, and whether is is using A1A or something instead of FSK?

Neil G4DBN


Re: GB3MCB current frequency?

Neil Smith G4DBN
 

I don't think it is locked, and it is miles off frequency.  This is an old trace from it in 2019 when it was hugely stronger.  The trace at present only shows up on a 262144-length FFT in Spectrum Lab and as a faint trace in WSJT-X at max contrast, hardly anything on the DUO IF trace even with contrast maxed.  My end is locked to a free-running Morion MV89A that is tweaked manually to within 10 Hz or so at 10 GHz.

The signal level feels slightly too steady, not scintillating like I'd expect with troposcatter. Also, there are no obvious doppler tracks or smears from the very few planes on the path.

I'll have another look later and see if it is still there.  This is with a 95cm dish up at 13m, waveguide relay and waveguide LNA, clear to the horizon out to 73km in that direction, so it isn't totally impossible.

Neil G4DBN

On 04/03/2021 22:23, Andy G4JNT wrote:
10Hz random wobble on 10GHz over a period of tens of seconds is typical of a GPSDO
Is 'MCB GPSDO locked ?




Re: ICNIRP

Stephen Tompsett
 

Someone suggested that I try Office365 to open the spreadsheet; It doesn't work for me I get the following error message:

We're sorry. We can't open the workbook in the browser because it uses these unsupported features:
• Custom toolbar attached to the workbook (also called attached toolbar)


On 04/03/2021 20:30, Stephen Tompsett wrote:

Having persuaded the spreadsheet to work (partially), the calculated horizontal distances appear to be ridiculous for  high gain antennas. While it may be necessary to allow a significant distance in the direction a high gain antenna is transmitting, the same distance cannot be required behind or to the side of such an antenna, where I would expect the required distance to be comparable to the distance required for an isotropic radiator or the near field value?

On 04/03/2021 06:17, GM6VXB via groups.io wrote:
Watching this thread with interest and will not reply to comments.
Have done two RF safety courses in my commercial life so do understand what is
and is not safe to be close to RF wise.
Have looked at both the RSGB (who are they) and OFCOM 'calculators' which although
almost correct do not really take into account the duty cycles involved in amateur radio.

Martin, GM6VXB
-- 
Stephen Tompsett (G8LYB)
Tel: 01788 578940
Mob: 07956 855816
-- 
Stephen Tompsett


Re: GB3MCB current frequency?

Andy G4JNT
 

10Hz random wobble on 10GHz over a period of tens of seconds is typical of a GPSDO
Is 'MCB GPSDO locked ?



On Thu, 4 Mar 2021 at 22:15, Neil Smith G4DBN <neil@...> wrote:

I'm seeing a very very weak trace on 10368.97056 MHz coming from the right direction to be GB3MCB. It is a little bit wobbly, by up to 10 Hz. It disappears when I beam away or elevate, but I don't see any obvious FSK.  I seem to remember that MCB used to have a very very narrow shift, and tended to bounce a bit during the keying cycles, but it is so long since I heard it last that I might be seeing something totally different.  Just seems concidence that the signal is in the right direction, and somewhere near the right frequency.  MCB is 460 km away, so no wonder it's weak, but this doesn't feel quite right.  Can anyone confirm what frequency MCB is on right now, and whether is is using A1A or something instead of FSK?

Neil G4DBN


GB3MCB current frequency?

Neil Smith G4DBN
 

I'm seeing a very very weak trace on 10368.97056 MHz coming from the right direction to be GB3MCB. It is a little bit wobbly, by up to 10 Hz. It disappears when I beam away or elevate, but I don't see any obvious FSK.  I seem to remember that MCB used to have a very very narrow shift, and tended to bounce a bit during the keying cycles, but it is so long since I heard it last that I might be seeing something totally different.  Just seems concidence that the signal is in the right direction, and somewhere near the right frequency.  MCB is 460 km away, so no wonder it's weak, but this doesn't feel quite right.  Can anyone confirm what frequency MCB is on right now, and whether is is using A1A or something instead of FSK?

Neil G4DBN


Re: ICNIRP

Stephen Tompsett
 

Having persuaded the spreadsheet to work (partially), the calculated horizontal distances appear to be ridiculous for  high gain antennas. While it may be necessary to allow a significant distance in the direction a high gain antenna is transmitting, the same distance cannot be required behind or to the side of such an antenna, where I would expect the required distance to be comparable to the distance required for an isotropic radiator or the near field value?

On 04/03/2021 06:17, GM6VXB via groups.io wrote:
Watching this thread with interest and will not reply to comments.
Have done two RF safety courses in my commercial life so do understand what is
and is not safe to be close to RF wise.
Have looked at both the RSGB (who are they) and OFCOM 'calculators' which although
almost correct do not really take into account the duty cycles involved in amateur radio.

Martin, GM6VXB
-- 
Stephen Tompsett (G8LYB)
Tel: 01788 578940
Mob: 07956 855816


Re: Wave guide dummy load.

Andy G4JNT
 

I'd have thought the uWave Column would be a better place.   

Is there really much interest in unknown quality loads in waveguide ?



On Thu, 4 Mar 2021 at 18:28, Greg - ZL3IX <zl3ix@...> wrote:
Since few of us will have a copy going so far back, how about repeating the design in RadCom. An idea for Design Notes, Andy (JNT)....?


Re: Wave guide dummy load.

Greg - ZL3IX
 

Since few of us will have a copy going so far back, how about repeating the design in RadCom. An idea for Design Notes, Andy (JNT)....?

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