Date   

Re: Electronic Design - Bizen

Alan Melia
 

Hi Chris interesting ! However acertain amount of BS :-)) I was around in fabrication when MOS started to appear. I took quite a while to really crack the technology and cleanliness to make CMOS work reliable with an economic yield. Piggy-backed on ion implantation and modern technologies it obviously has a chance of success. However when you realise a fab-line costs around $2b to build thereare a lot of hurdles to be overcome yet. I attended a symposium in1967 that predicted 3D GaAs would be all the rage.....we barely had UHF transistors then! I would query whether the ''need for speed'' on the large scale can still drive the kind of invertment required forward. Even smart(?)phone markets seem to be faltering.

But hell what do I know ?......I said mobile phones would never catch on !! :-))

Alan
G3NYK

----- Original Message -----
From: "Chris Bartram G4DGU" <chris@chris-bartram.co.uk>
To: <UKMicrowaves@groups.io>
Sent: Friday, June 26, 2020 2:34 PM
Subject: [UKMicrowaves] Electronic Design - Bizen


This isn't directly about microwaves, but the subject may interest a significant number of people who subscribe to this list.

<https://www.electronicdesign.com/power-management/whitepaper/21134181/are-quantumtunnel-transistors-real-and-what-do-they-mean-for-power-tech?utm_source=EG+ED+Today&utm_medium=email&utm_campaign=CPS200623031&o_eid=2591D6194345C9W&rdx.ident%5Bpull%5D=omeda%7C2591D6194345C9W&oly_enc_id=2591D6194345C9W>

73

Chris G4DGU



Re: Electronic Design - Bizen

Neil Smith G4DBN
 

Fine in Chrome, using Thunderbird mail client.

Neil G4DBN

On 26/06/2020 15:00, Simon Brown wrote:

Fine with Edge.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Andy G4JNT
Sent: 26 June 2020 14:44
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Electronic Design - Bizen

 

"Page isn't working" if you click the link direct

But, copy and paste between the angle brackets, it works

 

Andy

 

 

 



Re: Electronic Design - Bizen

Simon Brown
 

Fine with Edge.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Andy G4JNT
Sent: 26 June 2020 14:44
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] Electronic Design - Bizen

 

"Page isn't working" if you click the link direct

But, copy and paste between the angle brackets, it works

 

 

 


Re: Electronic Design - Bizen

Andy G4JNT
 

"Page isn't working" if you click the link direct
But, copy and paste between the angle brackets, it works



Electronic Design - Bizen

Chris Bartram G4DGU
 


Re: Design for unfolding portable dish

Chris Bartram G4DGU
 

There's information on stressed paraboloids in the presentation below:

http://www.eme2016.org/wp-content/uploads/2016/08/EME-2016-K2UYH-Presentation.pdf

73 from Ian GM3SEK

I didn't see K2UYH's presentation until quite recently, but there is another much older QST article - for which I've lost the reference - which covers the subject. IIRC it's part of a longer series(?) of contributions about the amateur reception of 2GHz comms directly from the Apollo Moon landers in the early 1970s.

I used a 12ft stress dish based on that work to hear my own (CW) Moon echoes on 1296 in about 1983 - 4. Unfortunately I had to take the dish down before I was able to make my first EME QSO on the band.

The K2UYH approach, using an offset reflector, suitably engineered, could make a practicable folding antenna. The major obstacle seems to be finding a suitably flexible material for the dish surface.

73

Chris G4DGU


Club 3 cms EME station in VK6

Keith
 

Greetings all,
Some of you may have already seen this on Moonnet but I wanted to post it here with some added comments.
Our local radio club VK6ANC ( NCRG Inc ) has voted to finance the 3cms EME station that myself, Larry VK6UM and Dean VK6DSL have been working towards for the past two years, a very large sum of money indeed :)
Initially this will involve a 2mtr dish on a Seatel fully tracking commercial mount that we have beefed up considerably and improved the control system.
As part of the proposal we submitted to the membership we have been asked to give an idea of just how many stations there are on 3 cms EME and how many are building towards this.
I've now found the basic information on PA0PLY's site and have supplied this to members. 
We have an excellent location in a wildlife heritage area approx 2 kms form the nearest housing ( OF78xe )
The vast majority of the 70 odd members are HF operators, only 5 or 6 of us are interested in the bands above 1 ghz.
We are planning on educating them :)
The station callsign will be VK6UW ( VK6µW ) and we were last in action when we operated on 6 cms from the 28 mtr dish just down the road, for the Apollo 50th Anniversary and had contacts with Goonhilly amongst others. We will have access to the dish again soon I'm lead to believe.
The reason for this message is to let folks know, and to show our members the interest out there on the higher bands.
That also leads us to preparing for the next stage once we are operational.
Anyone got a TWT for 24 ghz that they would like to part with please ??
We can also be on air with 24 ghz and either a 2.4 mtr dish or a 1.2 mtr dish from the same location, independently of the club at first, all thats stopping us is the power.
Everything else is here and waiting, so if you know anyone who would like to help put VK6 on the map again ( Rex VK7MO did it 3 years ago, some from my back yard ) please put them in touch with me initially and we will go from there.
We look forward to contacts with you all, the building is on its way, dish and gear ready, 100 watt TWT ready, transverter and lna etc ordered from Kuhne today, and we plan to be up and running well before Xmas.
Cheers all
Keith VK6KB/ VK6EME for the group


Re: Design for unfolding portable dish

Kevin G6UCY
 

Hi John

Antennas are always a bit of a compromise though, but I agree that despite being effective the design was probably not the sort of thing to take up a hill to make a few casual contacts.

Kevin G6UCY


Re: CAS-7A Satellite 10460 MHz downlink?

Neil Smith G4DBN
 

Lots of fun ahead, I foresee!

Neil

On 26/06/2020 12:33, Graham Shirville wrote:

Hi Neil,

I dont have much more info except that the IARU Coordination request form mentions 3cm AX.25 1Mbps GMSK Image data: 126Watts
(2W+18dBi Ant gain ) I would suggest that you contact Alan Kung BA1DU the operator listed here  http://www.amsatuk.me.uk/iaru/finished_detail.php?serialnum=658 for further info. There are a number of other upcoming space projects with !0.5GHz downlinks both in low earth orbits and for the Lunar Gateway in a HALO orbit around the moon.

73

Graham G3VZV

On 26/06/2020 11:51, Andy G4JNT wrote:
If it's designed to re-enter so soon, predictions will be a bit hit-and-miss anyway.  You'll be trying to get new Keps every day if you need that accuracy



On Fri, 26 Jun 2020 at 01:59, Neil Smith G4DBN <neil@...> wrote:
Is there any detail yet on the likely link budget and orbital parameters of the CAS-7A satellite scheduled fo launch later this year? Just wondering about tracking slew rates and dish sizes. Sounds like a bit of fun, taking video selfies from orbit as the sat whizzes over.
1Mbps GMSK on 10460 MHz is the plan, I understand. Doppler will be fun, but I need to get an idea of the peak slew rate I’ll need to follow passes with an az-el dish drive.

Has there been any further news on the CUAVA-1 sat with 5.7 and 76 GHz downlinks? I wonder if a bare diode harmonic mixer would be sensitive enough for the 76 G stuff?

Neil G4DBN


-- 
Neil
http://g4dbn.uk


Re: CAS-7A Satellite 10460 MHz downlink?

Neil Smith G4DBN
 

Project lifecycle for this will be me spending six weeks building and testing stuff, then running it for a few passes, then losing interest and fluttering off to the next project, so decay rates won't matter too much.

If it is in a 500km sun-synchonous orbit, I should be able to work out the peak slew rate from that. The graphic from "Portable Optical Ground Stations for Satellite Communication", K M Riesing (PhD thesis 2013) show the azimuth slew rates for different elevations.  Overhead passes are a nightmare for an az-el drive I guess?  Above 85 degrees you almost get into the 2DOF version of gimbal lock. Anything over 0.1 radians per second is going to be very difficult on the 3m dish, but with a 1.2m solid offset, I think I can manage with big DC servo drives.  There might be a better geometry, depending on the maximum northerly extent of the orbit, by mounting the elevation plane at an angle of 20 degrees or so towards the north.

Doppler on the 76GHz should be a max of +-1.5MHz if my sums are right

Neil G4DBN

On 26/06/2020 11:51, Andy G4JNT wrote:
If it's designed to re-enter so soon, predictions will be a bit hit-and-miss anyway.  You'll be trying to get new Keps every day if you need that accuracy



On Fri, 26 Jun 2020 at 01:59, Neil Smith G4DBN <neil@...> wrote:
Is there any detail yet on the likely link budget and orbital parameters of the CAS-7A satellite scheduled fo launch later this year? Just wondering about tracking slew rates and dish sizes. Sounds like a bit of fun, taking video selfies from orbit as the sat whizzes over.
1Mbps GMSK on 10460 MHz is the plan, I understand. Doppler will be fun, but I need to get an idea of the peak slew rate I’ll need to follow passes with an az-el dish drive.

Has there been any further news on the CUAVA-1 sat with 5.7 and 76 GHz downlinks? I wonder if a bare diode harmonic mixer would be sensitive enough for the 76 G stuff?

Neil G4DBN


-- 
Neil
http://g4dbn.uk


Re: CAS-7A Satellite 10460 MHz downlink?

Graham Shirville
 

Hi Neil,

I dont have much more info except that the IARU Coordination request form mentions 3cm AX.25 1Mbps GMSK Image data: 126Watts
(2W+18dBi Ant gain ) I would suggest that you contact Alan Kung BA1DU the operator listed here  http://www.amsatuk.me.uk/iaru/finished_detail.php?serialnum=658 for further info. There are a number of other upcoming space projects with !0.5GHz downlinks both in low earth orbits and for the Lunar Gateway in a HALO orbit around the moon.

73

Graham G3VZV

On 26/06/2020 11:51, Andy G4JNT wrote:
If it's designed to re-enter so soon, predictions will be a bit hit-and-miss anyway.  You'll be trying to get new Keps every day if you need that accuracy



On Fri, 26 Jun 2020 at 01:59, Neil Smith G4DBN <neil@...> wrote:
Is there any detail yet on the likely link budget and orbital parameters of the CAS-7A satellite scheduled fo launch later this year? Just wondering about tracking slew rates and dish sizes. Sounds like a bit of fun, taking video selfies from orbit as the sat whizzes over.
1Mbps GMSK on 10460 MHz is the plan, I understand. Doppler will be fun, but I need to get an idea of the peak slew rate I’ll need to follow passes with an az-el dish drive.

Has there been any further news on the CUAVA-1 sat with 5.7 and 76 GHz downlinks? I wonder if a bare diode harmonic mixer would be sensitive enough for the 76 G stuff?

Neil G4DBN



Re: CAS-7A Satellite 10460 MHz downlink?

Andy G4JNT
 

If it's designed to re-enter so soon, predictions will be a bit hit-and-miss anyway.  You'll be trying to get new Keps every day if you need that accuracy



On Fri, 26 Jun 2020 at 01:59, Neil Smith G4DBN <neil@...> wrote:
Is there any detail yet on the likely link budget and orbital parameters of the CAS-7A satellite scheduled fo launch later this year? Just wondering about tracking slew rates and dish sizes. Sounds like a bit of fun, taking video selfies from orbit as the sat whizzes over.
1Mbps GMSK on 10460 MHz is the plan, I understand. Doppler will be fun, but I need to get an idea of the peak slew rate I’ll need to follow passes with an az-el dish drive.

Has there been any further news on the CUAVA-1 sat with 5.7 and 76 GHz downlinks? I wonder if a bare diode harmonic mixer would be sensitive enough for the 76 G stuff?

Neil G4DBN



Re: Design for unfolding portable dish

Ian White
 

There's information on stressed paraboloids in the presentation below:

http://www.eme2016.org/wp-content/uploads/2016/08/EME-2016-K2UYH-Presentation.pdf

73 from Ian GM3SEK


On 24/06/2020 17:47, Nick Gregory G0HIK via groups.io wrote:

Ive done a couple of QO100 activations from fell tops now.
Ive used a 60 and a 80cm dish, anything else is just getting silly to backpack with.
I'm wondering if there are any designs for something that unfolds, about 1mtr and made from mesh for lightness and windloading I would think would be ideal.
I recall some satellites use something that unfurls and looks really cool.
But probably it would be a central hub and some canes stressed with a cord around the circumference.
Google seems not to be my friend in this case, microwave dish is not a useful search term ;).

Nick G0HIK


Re: Design for unfolding portable dish

John GM8OTI
 

Hi Kevin

It was OK but I didn't use it much because the assembly time was more than half an hour - quite fiddly. I guess you could probably find a quicker way of attaching the wire mesh panels than velcro tapes, but I did find it awkward.

Performance was good though, and with the mesh I obtained (just ordinary galvanized square mesh for fences etc. - what I would call chicken wire mesh) it was fine for 23cm and 13cm. It's quite easy to get a form close enough (within 1/10 wavelength) to a paraboloid with a stressed dish.

73
John GM8OTI


CAS-7A Satellite 10460 MHz downlink?

Neil Smith G4DBN
 

Is there any detail yet on the likely link budget and orbital parameters of the CAS-7A satellite scheduled fo launch later this year? Just wondering about tracking slew rates and dish sizes. Sounds like a bit of fun, taking video selfies from orbit as the sat whizzes over.
1Mbps GMSK on 10460 MHz is the plan, I understand. Doppler will be fun, but I need to get an idea of the peak slew rate I’ll need to follow passes with an az-el dish drive.

Has there been any further news on the CUAVA-1 sat with 5.7 and 76 GHz downlinks? I wonder if a bare diode harmonic mixer would be sensitive enough for the 76 G stuff?

Neil G4DBN


Re: Design for unfolding portable dish

Jules - M0UGA
 

Or there's my old favourite and known to many an Inmarsat user back in the day, the MTI TCS-7700 

Not cheap even now but beautifully made and constructed. Some have been converted to various different bands if you search around.

GL


Re: Design for unfolding portable dish

DF6NA Rainer
 


http://www.freepatentsonline.com/4683475.pdf

Am 25.06.2020 um 18:44 schrieb Andy GD1MIP:

A Robert Luly had a US patent for a folding parabolic in the early 70's.
Unfortunately I've never been able to track one down, but here's an old 1982 advert....

Or a 'Wrap-Rib' seems to be a similar thing from Lockheed in the US. All likely to be scarce in GB.  A few years ago a G6 put together a folding dish based on an umbrella,  but unfortunately I can't remember more or find a link.

Andy GD1MIP 


Re: Design for unfolding portable dish

Andy GD1MIP
 

A Robert Luly had a US patent for a folding parabolic in the early 70's.
Unfortunately I've never been able to track one down, but here's an old 1982 advert....

Or a 'Wrap-Rib' seems to be a similar thing from Lockheed in the US. All likely to be scarce in GB.  A few years ago a G6 put together a folding dish based on an umbrella,  but unfortunately I can't remember more or find a link.

Andy GD1MIP 


Re: Jupiter GPS boards

Roger Blackwell GM4PMK
 

On 25/06/2020 12:10, Paul M0EYT wrote:
Hi all,

I found a seam of Jupiter GPS boards whilst sorting through my junk shed, they are the ones with the 10KHz output, any use to anyone? You can have one (or N) for the cost of postage.

regards,

Paul M0EYT.
_._,_._,_


Hi Paul

If there's still one available, I'd appreciate it very much. I'm QTHR.

73

-- 

Roger Blackwell  GM4PMK

www.marsport.org.uk


Re: Jupiter GPS boards

Eddie G0EHV
 

Paul,
I have a use for one if possible.
Ok payment via PayPal for shipping?
Regards,
Eddie
G0EHV 

Launched into the ether from my iPad 

On 25 Jun 2020, at 14:42, Andy G4JNT <andy.g4jnt@...> wrote:

Beware, these boards may well not have coped with teh week rollover, and could be outputting a date exactly 1023 weeks ago
That may have a knock-on into leap second compensation, and epheris determination at boot up

Try it and see - the Bell Hill beacons use one, but as it's hardly ever been turned off in nearly 20 years and has battery backup (a 20+ year old NiCd )   perhaps we're just lucky



On Thu, 25 Jun 2020 at 14:34, g3zqu via groups.io <g3zqu=btinternet.com@groups.io> wrote:
Yes please a couple would be appreciated.
Qthr  ok, let me know postage.
Martin g3zqu

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