Date   

GB2RS on 10GHz via QO-100

Murray Niman
 

in this weeks GB2RS news....

QO-100 is a geostationary satellite with a footprint that covers Europe, Africa and India, so this news bulletin is a specially-adapted international version. The RSGB would like to thank AMSAT-DL for their kind cooperation in making this broadcast possible. If you don’t have any 10GHz equipment but would still like to monitor the broadcast, there is a dedicated webSDR at batc.org.uk that requires no radio equipment. Just click on the ‘on-line’ tab.


Listen out for its SSB on the narrowband transponder  - expected to be 10489.900 MHz  0900 UK local time

73

 Murray G6JYB


Re: Offset dish geometry

Neil Smith G4DBN
 

I think it is mainly about convenience of transport and packaging.  The shape of the outside is a projection of a cone with its vertex at the dish focus. It is usually a circular cone, but can be an ellipse, triangle, square or maple leaf or any cross-section you like, so long as the features at the edge are large compared to a wavelength to avoid diffraction and other weirdness. In general the projection of the cone needs to be ovoid if you want to have a flat rim and best stiffness.  Again, for convenience, the centre of the parabola usually coincides with the edge of the ovoid surface, but it doesn't need to. If the feedhorn is large, it is sometimes better if the cone is offset a bit more to reduce feed blockage.  One or two segments of an 8-segment PF dish work fine when used as an offset, so long as you can illuminate the resulting Dairy Lea Slice effectively

Neil G4DBN

On 30/04/2021 15:27, David Law wrote:
My 10gHz 1m Gibertini dish sits flat on the floor, im guessing most do.
_._,_._,_



Re: Activity List for the UK Microwave Group Low Band Contest - Sunday 2nd May

David Law
 

It takes me an hour and 15 to get to site and 30 to set up, 8am is a daft time to start the 10ghz Trophy. Id have to get up at 5am to go portable.
I think i'll go out on my motorbike instead if the weather is fit.

In response to the original question. I'm house viewing on the Saturday so will not be qrv unfortunately.


Re: Offset dish geometry

David Law
 

My 10gHz 1m Gibertini dish sits flat on the floor, im guessing most do.


Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Neil Smith G4DBN
 

Thanks for all of the suggestions and ideas. I'll get some quotes and see about ordering some PCBs so I can have a play. I've bought two of the CMPA901A035F devices, and the total I suggested before was indeed ex VAT, so the inclusive price, delivered, is £420 each.  It almost sounds cheap if you say it REALLY fast.

I am an expert investor in bottomless money-pits, me. Oh yes. Ask my wife.  Actually, on reflection, don't.

Neil G4DBN


Re: Activity List for the UK Microwave Group Low Band Contest - Sunday 2nd May

Adrian G4UVZ
 

Thanks all for the clarification..I will be on 10GHz on Sunday ...Zello and 144.390 MHz 
Adrian


Re: Activity List for the UK Microwave Group Low Band Contest - Sunday 2nd May

Adrian G4UVZ
 

On Thu, Apr 29, 2021 at 11:16 AM, Dave (G1OGY) wrote:
This is the problem of moving the 3cm trophy from Sat to Sun.
Bad idea IMHO.
It wasn't broke....

On Thu, 29 Apr 2021, 17:37 Neil Smith G4DBN, <neil@...> wrote:

The tricky point for me is if I work a station on 3cm in the RSGB UHF on Saturday, and want to work them again in the 3cm Trophy on Sunday, we both have to find a way to accept the dupes, or both close down the UHF contest and open the Trophy.  Also, how do I persuade someone not taking part in the Trophy to work me a second time as a dupe in the UHF so I can get the points in the Trophy?  Ok, they don't lose any points by scrubbing the first contact, but it's awkward, especially if the station is in EU.

Nothing to stop RSGB non-members from joining in the fun of the contest and giving points away, but they can only put in a checklog.  It would be huge fun if a non-member was to put in the highest score as a checklog.

Neil G4DBN

On 29/04/2021 16:40, John Quarmby via groups.io wrote:

Hi Adrian

There are several concurrent contests this weekend:

1. RSGB UHF Contest - this is all bands 432MHz - 245GHz, 1400 Saturday to 1400 Sunday (Coordinated with other EU contests)
2. RSGB 10GHz Trophy Contest - Runs 0800 - 1400 GMT Sunday
3. UK Microwave Group Low Band Contest - 1.3GHz to 3.4GHz runs 0800 - 1400 GMT Sunday.

The activity list is for the UKuG event on 1296, 2300, 2320, and 3400MHz.

73

John G3XDY

On 29/04/2021 15:27, Adrian G4UVZ via groups.io wrote:
I am easily confused !  Is 10 GHz included in this cantest ? I can only see Ben mentioning 10GHz and something about a trophy on a Sunday..not sure if that is this Sunday?

Adrian
 


Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Dominique Dehays
 

Gm all,

I agree with G4DBN that a waveguide transition at the output will be better. Maybe this one would be more reliable if it is solid copper rather than a microstrp launcher.
See for exemple what has been done with our 24 Ghz 5w amps.

73
Dom



Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Dave G8KHU
 

Rogers certainly do this - their Lo-Pro range - as  well as the deposited versions. I'm sure other manufacturers offer it too.
https://rogerscorp.com/-/media/project/rogerscorp/documents/advanced-connectivity-solutions/english/data-sheets/ro4000-lopro-laminates.pdf

<< it would be more sensible to use a laminate with a glued (pressed) layer of copper (I don't remember the type) than electrochemically applied , in which the copper layer on the laminate side is uneven and causes losses due to surface conduction of microwaves
73's de Staszek SP6GWB>>

Dave G8KHU


Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Stanislaw Ziemczonek
 

Neil,
Considering Kent's comments, it would be more sensible to use a laminate with a glued (pressed) layer of copper (I don't remember the type) than electrochemically applied , in which the copper layer on the laminate side is uneven and causes losses due to surface conduction of microwaves
73's de Staszek SP6GWB

Most of the RF field is between the Copper Trace and the Ground Plane.
Some Silver on top of the PCB trace will have very little effect on losses.
Kent WA5VJB



On 29/04/2021 12:17, Neil Smith G4DBN wrote:
> I need to get some silver-plated PCBs made for high power 10 GHz SSPAs
> using CMPA0901A035 and CMPA0801B025 devices. I'll be soldering the
> PCBs into a milled copper housing.
>
> Does anyone have experience of PCB fabs who can do immersion silver
> finish on Rogers, Arlon, Isola and similar SHF laminates? I've had a
> quote from Eurocircuits and I've used them previously. I know there
> are some Chinese fabs that can do silver, but it is an expensive
> business and I want to be 100% sure of the quality.
>
> I need the boards milling with rounded corners and a pocket for the
> devices.  I'd like solder resist if that is an option, so I can do
> reflow of the passives and thermal monitor chips without them sliding
> about the place.
>
> Price for a 40 x 40 mm board in 30-off, with milling, silvering and
> resist on an I-Tera laminate is about £12 each for 5 day service from
> their Hungary/Germany fabs. Rogers 4350 is about £2 extra. RO4003C
> needs a special quote. Anyone know of a supplier with these
> capabilities that offers better pricing?
>
> Neil G4DBN
>
>
>
>
>
>

--
This email has been checked for viruses by AVG.
https://www.avg.com








First UK contact on 30THz video

Barry Chambers
 

GM Folks

a short snapshot of the first UK contact on 30THz. The complete saga lasted for 4 hours!

https://www.youtube.com/watch?v=zXwlRLPQBO0

--
73
Barry, G8AGN


Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Tim, VK2XAX
 

Hi Stefan,

The CMPA801B025F is ~$635 from Mouser in AU

https://au.mouser.com/ProductDetail/Wolfspeed-Cree/CMPA801B025F?qs=FhbYA5MVMOWms%252Bq06Tnnjw%3D%3D

The CMPA901B035F is ~$611 from Mouser in AU

https://au.mouser.com/ProductDetail/Wolfspeed-Cree/CMPA901A035F?qs=BJlw7L4Cy78O8lOH7Btn7w%3D%3D

Why the higher power part costs less is a mystery!

regards

Tim

On 30/4/21 9:11 am, Stefan wrote:
Neil

How many dollars are those devices?
--
VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA


Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Stefan
 


ah cheers Neil thank you

----- Original Message -----
Sent: Friday, April 30, 2021 9:33 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?

Mouser list them at £350 delivery and duty paid, so that should include local UK purchase tax. Digikey have no current stock. Verical and Arrow have stock. Not sure of the dollar price, have a look on Octopart or try to beg a sample from Wolfspeed? 

They will need a declaration of use statement and may not ship to some locations (at least that’s what happened with my 025 device).

https://au.mouser.com/ProductDetail/Wolfspeed-Cree/CMPA901A035F shows 622 AUD

Neil G4DBN



On 30 Apr 2021, at 00:11, Stefan <comlab@...> wrote:

Neil

How many dollars are those devices?

Stefan
----- Original Message ----- From: "Neil Smith G4DBN" <neil@...>
To: <UKMicrowaves@groups.io>
Sent: Friday, April 30, 2021 8:40 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?


typo sorry, missed the 1.

https://www.mouser.co.uk/datasheet/2/90/CMPA901A035F-1665444.pdf

and

https://www.mouser.co.uk/datasheet/2/90/cmpa801b025-876408.pdf for the older one I have.

Neil G4DBN

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim












Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Neil Smith G4DBN
 

Mouser list them at £350 delivery and duty paid, so that should include local UK purchase tax. Digikey have no current stock. Verical and Arrow have stock. Not sure of the dollar price, have a look on Octopart or try to beg a sample from Wolfspeed? 

They will need a declaration of use statement and may not ship to some locations (at least that’s what happened with my 025 device).

On 30 Apr 2021, at 00:11, Stefan <comlab@...> wrote:

Neil

How many dollars are those devices?

Stefan
----- Original Message ----- From: "Neil Smith G4DBN" <neil@...>
To: <UKMicrowaves@groups.io>
Sent: Friday, April 30, 2021 8:40 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?


typo sorry, missed the 1.

https://www.mouser.co.uk/datasheet/2/90/CMPA901A035F-1665444.pdf

and

https://www.mouser.co.uk/datasheet/2/90/cmpa801b025-876408.pdf for the older one I have.

Neil G4DBN

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim












Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Stefan
 

Neil

How many dollars are those devices?

Stefan

----- Original Message -----
From: "Neil Smith G4DBN" <neil@g4dbn.uk>
To: <UKMicrowaves@groups.io>
Sent: Friday, April 30, 2021 8:40 AM
Subject: Re: [UKMicrowaves] PCB fab for SHF laminates with immersion silver plating and solder resist?


typo sorry, missed the 1.

https://www.mouser.co.uk/datasheet/2/90/CMPA901A035F-1665444.pdf

and

https://www.mouser.co.uk/datasheet/2/90/cmpa801b025-876408.pdf for the older one I have.

Neil G4DBN

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim




Re: ebay changes

 

On Thu, 29 Apr 2021 at 21:40, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Not operational I know but we all buy/sell from it.
Anyone else concerned about ebays requirement that you let them have your bank details for direct payment rather than use Paypal. Strikes me that if they get hacked its just another way into one's private data for the thieves.
Maybe opening a separate bank account is the answer?
Ben
No I stick my company bank details on the web, so people can pay into the account.


However, the fact that one has to deliver the product before getting paid annoys me. Some products I sell use expensive parts and I will only buy the parts if someone pays me the money. Previously I got the money in my PayPal account immediately, which I could then buy parts with. But if I sign up to eBay's "Delayed payments" (they call it managed payments), then I will not get the money. I have not signed up, so can't list anything else. They keep threatening to remove my listings since I have not signed up for delayed payments, but so far they have not done so.

Most people realise from my auctions my company name, Google it, then find the item cheaper on my website, so I most sales don't come by eBay now.

I guess eventually; I will have to sign up for delayed payments, but I will leave it as long as I can.

Dave





Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Neil Smith G4DBN
 

On 29/04/2021 23:16, Tim, VK2XAX wrote:
Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim


Re: PCB fab for SHF laminates with immersion silver plating and solder resist?

Tim, VK2XAX
 

Hi Neil,

The mob in China I used for the 122GHz boards do Rogers with Silver, Gold or Tin plating.

Specifically they will do RO4350B, RO4003C, RO3003, RO3010 & RT5880.

https://www.pcbcart.com/pcb-fab/high-frequency-pcb.html


Can you point me at the data sheets for the CMPA's? A quick google didn't find anything!

cheers

Tim

--
VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA


Re: ebay changes

Andy
 

On 29/04/2021 21:50, Andy G4JNT wrote:
No.
Bank details are not generally considered to be a secret
Many organisations openly publish theirs for people to pay in.
Andy
www.g4jnt.com <http://www.g4jnt.com>
Exactly. Every cheque ever used has your bank details on it and people were happy to pass them around.


Re: ebay changes

G0FCU
 

eBay don't own PayPal directly anymore so are trying to cut them out when you SELL on eBay.

The key point is that the expensive PayPal charges won't be incurred (you'll pay eBay the charges instead but they will be a little cheaper). eBay will also be able to offer alternative ways for buyers to pay.

You don't have to give them your bank details but may be restricted on what you can sell in the future.

A good explanation is:

Simon
G0FCU.



On Thu, 29 Apr 2021, 21:50 Andy G4JNT, <andy.g4jnt@...> wrote:
No.
Bank details are not generally considered to be a secret
Many organisations openly publish theirs for people to pay in.



On Thu, 29 Apr 2021 at 21:40, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:

Anyone else concerned about Ebay's requirement that you let them have your bank details for direct payment rather than use Paypal? Strikes me that if they get hacked it's just another way into one's private data for the thieves.


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