Date   

Re: January SHF UKAC

Robin Szemeti - G1YFG
 

I'll be on 13cm, hopefully a little more stable than previous attempts now I have made a copper box for the transverter with proper feedthroughs, it may be less prone to oscillation.

I have a PA for 6cm coming that I will be trying EME with, but I may try a little terrestrial with it also, but not ready for this month.


On Mon, 25 Jan 2021 at 14:58, G1DFL via groups.io <peterdwberkshire=yahoo.com@groups.io> wrote:
I'll attempt 3cm and 6cm SSB from home, for the January SHF UKAC.

Will have KST, Zello and 144.390MHz SSB.
Not holding out for many QSO's, but we shall see.

Hopefully the snow will have melted by then, otherwise assembling all of the portable kit on the back lawn will be somewhat interesting.

Hope to work a few of you local to me in IO91 so sub-100km paths, and maybe out to 150km.
Who else plans to be on?

Regards..Pete
G1DFL


--
Robin Szemeti - G1YFG


January SHF UKAC

G1DFL
 

I'll attempt 3cm and 6cm SSB from home, for the January SHF UKAC.

Will have KST, Zello and 144.390MHz SSB.
Not holding out for many QSO's, but we shall see.

Hopefully the snow will have melted by then, otherwise assembling all of the portable kit on the back lawn will be somewhat interesting.

Hope to work a few of you local to me in IO91 so sub-100km paths, and maybe out to 150km.
Who else plans to be on?

Regards..Pete
G1DFL


Gap Waveguides

Chris Bartram G4DGU
 

Hello Ethan

The problem (for me) with components involving metasurfaces, such as in a a gap waveguide is that they need a different sort of approach to conventional TEM/TM/TE waveguides. Although I'm more-or-less comfortable with conventional waveguide structures, I don't feel competent to give an answer, as my involvement with metasurfaces has been rather cursory.

There is quite a literature on the subject, and it is probably worth starting a search on-line away from the amateur literature. If you can find back issues of the IEEE Microwave Theory and Techniques Society Magazine, you may well be able to find an introductory paper. I think I remember reading rapidly through one a couple of years ago. There are also a several books on metasurfaces - but be prepared for some difficult (at least for me!) maths.

Iin another life, I did have some experience of electroforming. Trom what I remember, copper requires a lot of care, and the careful selection of plating currents to get to a suitably small 'grain' size in the deposited metal. Particularly am mmWave frequencies, this will be very important in getting the lowest losses in an electroformed structure.

I hope these are useful comments.

73 Chris  G4DGU

G4DGU


Re: ERA-02 as a multiplier

Dominique Dehays
 

Hi ,

The 723 regulator is an excellent device and  much better than the 317 regarding noise
73
Dom


Re: ERA-02 as a multiplier

Greg - ZL3IX
 

Thanks for that Andy - very encouraging, and I'll try it out.


Re: ERA-02 as a multiplier

Greg - ZL3IX
 

I still use the occasional 723 regulator, especially if I want variable current limit. I also first came across them in 1974, immediately after graduating. I don't think the internal ref can be just a zener; it's too stable for that.


Re: ERA-02 as a multiplier

Colin Ranson
 

Andy, I just happened to have two separate 723’s on a piece of veroboard that came with a W1GHz  simple personal beacon for 10GHz. (bought at a uW MRT many years ago) Each one was used to control the bias on the Multiplier MODAMPS.

 

Just seemed handy to use !   I will of course use something more appropriate like an LDO1117 adj. Or similar when I lay out the PCB.

 

Colin de ‘LBS.

 

 

Sent from Mail for Windows 10

 

From: Andy G4JNT
Sent: 24 January 2021 22:30
To: UK Microwaves groups.io
Subject: Re: [UKMicrowaves] ERA-02 as a multiplier

 

Ouch

Still using the 723 regulator?

That thing is so complicated to connect up compared with an LM317.  And, I believe, a lot noisier.   

Isn't it so old that the reference inside it is an actual Zener?  If so, no wonder it's noisy.

I formally learnt about them in 1976 - remember it well.

 

Andy

 

 

 

On Sun, 24 Jan 2021 at 22:26, Colin Ranson <g8lbs@...> wrote:

Greg,

 

The Gali-2 is good to 8GHz.......    I ‘rats nested’ one from 1278 – 2556MHz, think I set bias at about 2.2-2.5V with a 723 regulator. Yet to build on a proper PCB.

 

Regards

 

Colin de G8LBS.

 

 

Sent from Mail for Windows 10

 

From: Greg - ZL3IX
Sent: 24 January 2021 19:36
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] ERA-02 as a multiplier

 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.

 

 


Re: Gap Waveguides

Ethan Waldo
 

Thanks for responding.  As I said copper electrodeposition seems feasible for amateurs and gets from 4um to 400um accuracy in lieu of micromachining, but is a lot slower.  I'm curious if air is the effective dielectric, do you use a dielectric constant of 1 in calculations or some very small number?


Re: ERA-02 as a multiplier

Andy G4JNT
 

Ouch
Still using the 723 regulator?
That thing is so complicated to connect up compared with an LM317.  And, I believe, a lot noisier.   
Isn't it so old that the reference inside it is an actual Zener?  If so, no wonder it's noisy.
I formally learnt about them in 1976 - remember it well.



On Sun, 24 Jan 2021 at 22:26, Colin Ranson <g8lbs@...> wrote:

Greg,

 

The Gali-2 is good to 8GHz.......    I ‘rats nested’ one from 1278 – 2556MHz, think I set bias at about 2.2-2.5V with a 723 regulator. Yet to build on a proper PCB.

 

Regards

 

Colin de G8LBS.

 

 

Sent from Mail for Windows 10

 

From: Greg - ZL3IX
Sent: 24 January 2021 19:36
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] ERA-02 as a multiplier

 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.

 


Re: ERA-02 as a multiplier

Colin Ranson
 

Greg,

 

The Gali-2 is good to 8GHz.......    I ‘rats nested’ one from 1278 – 2556MHz, think I set bias at about 2.2-2.5V with a 723 regulator. Yet to build on a proper PCB.

 

Regards

 

Colin de G8LBS.

 

 

Sent from Mail for Windows 10

 

From: Greg - ZL3IX
Sent: 24 January 2021 19:36
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] ERA-02 as a multiplier

 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.

 


Re: ERA-02 as a multiplier

geoffrey pike
 

But when you get to 10.5 GHz you will probably want to amplify that so perhaps just get a handful of NLB-310 from the outset
(which i use in my multiplier), But perhaps you have a handful of ERA-02s that you want to use up. 
cheers
Geoff
GI0GDP
(-2C outside)

On Sunday, 24 January 2021, 19:36:57 GMT, Greg - ZL3IX <zl3ix@...> wrote:


Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


Re: ERA-02 as a multiplier

Andy G4JNT
 

Yes, I've used then for both X3 and X4 to 10GHz.  They work very well.   Operate at a bit lower than the recommended bias level to increase non-linearity.
IIRC, I got something like 0dB tripler gain at 0dBm.   May have remembered that wrongly tho.
Try it and see - play with the optimum biassing.

And, BTW,   an MSA family modamp was used as a doubler in the Inmarsat-3 satellite, in the frequency generator module.
So if it's good enough for a spacecraft ...



On Sun, 24 Jan 2021 at 19:36, Greg - ZL3IX <zl3ix@...> wrote:
Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


Re: ERA-02 as a multiplier

KENT BRITAIN
 

According to Zack at the ARRL, they have modest harmonics out to 24 GHz.
Kent  WA5VJB/2E0VAA


On Sunday, January 24, 2021, 01:36:57 PM CST, Greg - ZL3IX <zl3ix@...> wrote:


Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


ERA-02 as a multiplier

Greg - ZL3IX
 

Does anyone have experience of using the ERA-02 as a tripler from around 3.5 GHz to around 10.5 GHz? I know they work in triplers up to 3 GHz, but I was wondering whether they have a respectable performance higher up, or whether one needs to use an MMIC that actually has some gain at 10 GHz.


Re: Are LEDs a noise source

Neil Smith G4DBN
 

Perhaps adding a piezo element and lightweight front-silvered mirror on a low-mass flexure into the path would give sufficient bandwidth for modulation into the kHz range so you could drive it directly with soundcard output from WSJT-X.

Neil G4DBN

On 24/01/2021 19:09, KENT BRITAIN wrote:
We mechanically modulated ours.  Much easier!  
Simplest was to just run the beam though the blades of a muffin fan. 
Turning the fan at about a 45 deg angle greatly improved the on to off ratio.  
With a more controlled motor and disk with a pattern of holes,   
 precise modulation tones can be produced.
  Kent

On Sunday, January 24, 2021, 12:16:44 PM CST, Robin Szemeti - G1YFG <robin@...> wrote:


It is *quite bright*, sets fire to the shed door ... pulls 30 amps from the mains, watercooled.  The usual lamp-pumped YAG laser with a ktp, so not a gas laser. This one is q switched to improve the efficiency of the ktp frequency double The Q-switch is fed with RF at about 100MHz, which can be gated with TTL logic.  I'll have to experiment with pulse rates one day.

On Sun, 24 Jan 2021 at 18:05, Andy G4JNT <andy.g4jnt@...> wrote:
Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG

--
Robin Szemeti - G1YFG
-- 
Neil
http://g4dbn.uk


Re: Are LEDs a noise source

KENT BRITAIN
 

We mechanically modulated ours.  Much easier!  
Simplest was to just run the beam though the blades of a muffin fan. 
Turning the fan at about a 45 deg angle greatly improved the on to off ratio.  
With a more controlled motor and disk with a pattern of holes,   
 precise modulation tones can be produced.
  Kent

On Sunday, January 24, 2021, 12:16:44 PM CST, Robin Szemeti - G1YFG <robin@...> wrote:


It is *quite bright*, sets fire to the shed door ... pulls 30 amps from the mains, watercooled.  The usual lamp-pumped YAG laser with a ktp, so not a gas laser. This one is q switched to improve the efficiency of the ktp frequency double The Q-switch is fed with RF at about 100MHz, which can be gated with TTL logic.  I'll have to experiment with pulse rates one day.

On Sun, 24 Jan 2021 at 18:05, Andy G4JNT <andy.g4jnt@...> wrote:
Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Robin Szemeti - G1YFG
 

It is *quite bright*, sets fire to the shed door ... pulls 30 amps from the mains, watercooled.  The usual lamp-pumped YAG laser with a ktp, so not a gas laser. This one is q switched to improve the efficiency of the ktp frequency double The Q-switch is fed with RF at about 100MHz, which can be gated with TTL logic.  I'll have to experiment with pulse rates one day.

On Sun, 24 Jan 2021 at 18:05, Andy G4JNT <andy.g4jnt@...> wrote:
Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Andy G4JNT
 

Ah, didn't read the footnote.  It's not a SS laser :-)

80W Green !
Don't shine that at any aircraft



On Sun, 24 Jan 2021 at 18:03, Andy Talbot <andy.g4jnt@...> wrote:
You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Andy G4JNT
 

You should be able to modulate a solid state laser at many tens of kHz,   More than enough to use with all the MFSK modes as a subcarrier



On Sun, 24 Jan 2021 at 17:52, Robin Szemeti - G1YFG <robin@...> wrote:
I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W

On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG


Re: Are LEDs a noise source

Robin Szemeti - G1YFG
 

I have a small green laser [1] that can be pulsed by controlling the Q-switch, I would think tones of a few hundred hertz would be possible ... I've been trying to find a sensible use for it for years ...

[1] 80W


On Sun, 24 Jan 2021 at 17:02, Neil Smith G4DBN <neil@...> wrote:
Back on to the original topic for a second, there are some articles
showing what appears to a forward-biased LED used as a noise source. The
author in this piece says the noise was about 6dB down on a zener in the
same topology (two-transistor amplifier). http://www.n5ese.com/noise.htm

I did wonder if the LED was drawn incorrectly and it was actually being
used in reverse breakdown.  The diagram towards the end of the page
definitely shows it drawn in the forward conduction direction.

LEDs do show some rising levels of shot noise and 1/f noise below 10
kHz, but that is at low levels. However, at high currents, the authors
found a correlation between the LF noise and the brightness fluctuations
of the LED in that frequency range.

https://www.researchgate.net/profile/Michael_Shur2/publication/268362232_titleLow_frequency_noise_of_light_emitting_diodes_Invited_Papertitle/links/54bcea0f0cf29e0cb04c55e3/titleLow-frequency-noise-of-light-emitting-diodes-Invited-Paper-title.pdf

There is another article using a totally different topology where a LED
and photodiode are used to generate noise with 7dB ENR up to about 100
MHz, but it hits the usual 1/f noise issues.
https://electronicprojectsforfun.wordpress.com/making-noise/noise-sources-i-have-built/a-led-photodiode-noise-source/

I've done this at extremely low light levels to make a "Quantum" random
pulse generator, but that's well away from the OP's question.

Neil G4DBN








--
Robin Szemeti - G1YFG

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