Date   

Can someone design me an S-Band microstrip filter

Andy G4JNT
 

I don't have much in they way of microstrip design software, and the learning curve is too long to start playing  - especially at this time of year, so:

Is there anyone so au-fait with a microwave / microstrip design package that this spec for a comb line bandpass filter is plug-N-play?   I'm after a 1:1 PCB artwork in some common graphics format like PDF that can just be dropped onto acetate to etch.    Don't mind playing with scalpels and bits of copper foil to do the fine tuning on the fingers, but need to be pretty much there straightaway with finger spacing

Passband to cover 2290 - 2460MHz or even a bit wider, ripple  <0.5dB
Fourth or  higher - not concerned how high it has to go.
Rejection at 2306 >40dB (highest LO)    and > 70dB at 2162MHz (highest image)
Loss isn't terribly important as it'll be for interstage use.

PCB material 0.8mm  Er 2.50   copper thickness 35um
Think it's RT-Duroid, I do have a fair bit of that PCB material in the junk box and it's about time it was used for something useful. 
Measured the Er and it does come out close to 2.50
 
I reckon  you can guess the application.   It's the only uWave band I don't have a 144MHz drive transverter for, so might as well make it cover the full allocation in one go.

TIA 


Re: Gunns

Paul Evans W4/VP9KF
 

Sorry, before my time - graduated in 1979. Strangely Southampton was on my 'list of 5' when applying, but never went for an interview, never mind a talk.

The person who gave you the talk would have been from Caswell Research and could have been Fred Myers (tall, dark haired guy) or Jim Turner (short, orange-ish hair and beard). They were in on making the worlds first MMICs, before USA, etc. It could have been someone else, they were very heavy into GaAs and epitaxy [vapour phase and later MOCVD].

I did use a GAT3 and GAT5 at one time - they were as rare as hens teeth! If their yield was anything like the normal Caswell yield then that's why they were rare :-(

Most Malvern things didn't end well. So the multi Gunn thing was probably abandoned and done an easier way. All I do know is that they didn't exactly have repeatability on their side. The most notable being the long held rumour that one day they made a 'magic' wafer which produced some Gunns that were twice+ as efficient as any recorded before or since [and exceeded theoretical power yield too]. We never saw anything like that in production, or we would have chased it HARD.

By the way, I did noise test measurements on our devices vs. the competition (Alpha, M/A, etc.) and confirmed what our customers were saying when ordering. We were waaaaay ahead on phase noise and stability. It was down to our epitaxy and not our fab (as I later proved). In the 80s all of the temporary traffic light heads were coming from us, radar speed meters (Escort, etc.) as well as buckets full of supermarket door openers! Of course, the military side was a little harder to yield. What few would know is that every wafer was run down the line to full mil. spec. until being dropped in superiority at test to 'commercial use'.
--
73, Paul Evans G4BKI [VP9KF]


Next RadCom DATA Column

Andy G4JNT
 

The deadline for August's issue is approaching and I'm at a loss what to cover  this time.    
So if anyone is doing anything interesting that would be applicable to the column, can you let me know please - ideally by Friday.


Re: 10GHz SMA to WG16

Gareth G4XAT
 

Brass it was, only room for two tuning screws, one opposite the probe (hole already there) and one 9.3mm upstream. Working well across the shack. Going to try the garden next. Any excuse for a bit of sunshine....
Gareth


Re: Gunns

Paul G8KFW
 

Hi Paul

I have a number of gun diodes but do not know their polarity can you help me on how to test them and determine their polarity without destroying them

Regards Paul

-----Original Message-----
From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Paul Evans W4/VP9KF
Sent: 09 June 2021 13:16
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Gunns

Well, I was the 2T [two terminal] Device Manager at Plessey Microwave, so I should be able to help you :-) My coverage was from wafer selection and test, epitaxy for all the devices we made, cleanroom design and monitoring, process control and modification, chip and wire bonding, packaging, test and installation into product. I also covered varactors, detectors, IMPATTs and TRAPATTs.

First, Gunns are not diodes, but they became known as that pretty universally by mistake in the 60s. Secondly, they only display negative resistance above a certain voltage where RF also starts to be generated under the right conditions. Despite extremely tight measurement and QA I used to say 'every single device we make is different'. I never saw any attempt at combining the output of two devices and I would give it zero chance of working (even if only for a very short time under just the right conditions - mostly thermal). I know of several systems where we would dearly have liked to combine devices outputs for more power!

Before having all the above dropped into my hands, I was an oscillator designer and I can tell you that Gunns have to be in just the right place to achieve oscillation and matching to their (cavity) environment and other [detection or varactor] devices. Redesigning a 22GHz design to get a reasonable number of man-hours to make one work was a case of going back to fundamental design yet making it look the same on the outside.

Taking really cheap diecast oscillator cavities and turning them into transitions seems like making life overly difficult. Try using an established design.
--
73, Paul Evans G4BKI [VP9KF]

P.S. I was fortunate to have studied under Prof. Paul Butler at University of Warwick who 'wrote the book' on hot electron theory which matched John Gunn's achieved best-case Gunn performance, amongst other things.








--
Paul Bicknell G8KFW   South Coast UK


Re: N plug solder for semi rigid

Paul G8KFW
 

Hi Keith  

 

I thought the request was for N connectors  for semi rigid

 

On looking at their web site www.coax-connectors.com I can only raise the following

 

BNC Adapters rated at 18 Ghz    when the construction of the BNC connector causes issues at 1.4 ghz  so any professional would limit them to 1000 Mhz and usually 500 Mhz

Please note the TNC is a different connecter when it is used above 1 Ghz as it outperforms the BNC

 

PL259  connecters  are listed UHF connecters  and 50 ohm    they do not have a fixed impedance  but to their credit  the technical spec rates them up to 300 Mhz  but  even at 140 mhz  they can cause large SWR mismatches

 

The Belling lee coax connecter used on domestic TV  are called PAL  or euro connectors    please where did this name come from  ?  we should Preserve the British names

 

I would love to test their right angle N connector  as it is rated at 18 Ghz   as most right angle connecters suffer with problems below 10 Ghz  and so are not suitable above 7 Ghz

 

I realise others might not agree  but you have to have checked connectors using test equipment not just used them  

 

Regards Paul

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Keith Le Boutillier via groups.io
Sent: 09 June 2021 09:14
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] N plug solder for semi rigid

 

Good morning all

 

See www.coax-connectors.com

 

They are UK based and have a full range of full spec connectors. I have always found them very helpful, just a happy customer

 

73 Keith GU6EFB

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of alwyn.seeds1
Sent: 09 June 2021 08:52
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] N plug solder for semi rigid

 

Dear Ben,

 

This is now a bit of a challenge.

 

Tyco moved their production to China and the designs are different from the ex-Greenpar ones.

 

There are many distributors of N connectors who are selling parts with poor design/poor tolerances- I have measured these and they show worse return loss than what used to be available.

 

Huber and Suhner are good, also Telegartner as a lower cost option, if they meet your spec.

 

Radiall have moved the production of a lot of their N connectors to China. I have measured some samples of these and they are within spec.

 

Cinch have introduced some low spec. ranges, check spec. carefully.

 

Likewise Amphenol.

 

So, I think you now have to check spec. very carefully, and do n’t be surprised if a connector that meets the MIL spec. to 12 GHz or 18 GHz is quite pricey.

 

So far as I know, there is no longer any manufacture of N connectors in the UK.

 

Regards,

 

Alwyn G8DOH

 

 

_____________________________________________________

 

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.

_____________________________________________________

 


--
Paul Bicknell G8KFW   South Coast UK


Re: N plug solder for semi rigid

alwyn.seeds1
 

Dear Keith,

Coax-connectors are indeed UK based. I do not know where the connectors they sell are manufactured.

I note that performance data for the connectors they sell is not on their web-site, but has to be requested.

I have tested a few samples of their N connectors. I measured the return loss to be higher than for equivalent connectors made by Radiall, which are, of course more expensive.

A coaxial connector requires precision mechanical engineering and stringent materials selection- these do not come cheap.

When the applications for these connectors were primarily military, MIL-spec. connectors were commonly available and purchasing was straight-forward.

Those days are gone, so care is required, particularly for use above 1 GHz.

Regards,

Alwyn

_____________________________________________________

Alwyn Seeds, Director
114 Beaufort Street (Management) Company Ltd.,
114 Beaufort Street,
London,
SW3 6BU

114 Beaufort Street (Management) Company Ltd., Registered in England and Wales: No. 02797775 Registered Office Address: 114 Beaufort Street, London, SW3 6BU
______________________________________________________


Re: Gunns

Andy G4JNT
 

Paul, can you remember if you gave a talk on GaAs to Southampton University electronics students in 1979 or 1980?  Think it was given by a Plessey chap
I remember the talk was 'optional', but of course I went to it.   A few months later, in the RF and Microwaves Finals exam paper was a question "Write an essay entitled 'Gallium Arsenide, the Microwave Material' "
A few buzz-words like 'high-mobility', 'bulk effect' and 'FETs' (very new in in 1980) and there was full marks awarded.  
ISTR getting something like 95% in that paper



On Wed, 9 Jun 2021 at 13:16, Paul Evans W4/VP9KF <paul@...> wrote:
Well, I was the 2T [two terminal] Device Manager at Plessey Microwave, so I should be able to help you :-) My coverage was from wafer selection and test, epitaxy for all the devices we made, cleanroom design and monitoring, process control and modification, chip and wire bonding, packaging, test and installation into product. I also covered varactors, detectors, IMPATTs and TRAPATTs.

First,  Gunns are not diodes, but they became known as that pretty universally by mistake in the 60s. Secondly, they only display negative resistance above a certain voltage where RF also starts to be generated under the right conditions. Despite extremely tight measurement and QA I used to say 'every single device we make is different'. I never saw any attempt at combining the output of two devices and I would give it zero chance of working (even if only for a very short time under just the right conditions - mostly thermal). I know of several systems where we would dearly have liked to combine devices outputs for more power!

Before having all the above dropped into my hands, I was an oscillator designer and I can tell you that Gunns have to be in just the right place to achieve oscillation and matching to their (cavity) environment and other [detection or varactor] devices. Redesigning a 22GHz design to get a reasonable number of man-hours to make one work was a case of going back to fundamental design yet making it look the same on the outside.

Taking really cheap diecast oscillator cavities and turning them into transitions seems like making life overly difficult. Try using an established design.
--
73, Paul Evans G4BKI [VP9KF]

P.S. I was fortunate to have studied under Prof. Paul Butler at University of Warwick who 'wrote the book' on hot electron theory which matched John Gunn's achieved best-case Gunn performance, amongst other things.






Re: Gunns

Andy G4JNT
 

At Malvern, in 1977, they had ten or twenty or so Gunns successfully running together in a development aimed at a personnel detector radar (Doppler, like traffic radars) 
Don't know the exact details, but he said it was quite a simple arrangement, with the Gunns mounted periodically along the waveguide.
I know this coz a fellow MoD student engineer was on the project for his summer placement and knew my interest in Am. microwaves

I'm guessing the Gunns would be mounted a guide wavelength apart.



On Wed, 9 Jun 2021 at 13:16, Paul Evans W4/VP9KF <paul@...> wrote:
Well, I was the 2T [two terminal] Device Manager at Plessey Microwave, so I should be able to help you :-) My coverage was from wafer selection and test, epitaxy for all the devices we made, cleanroom design and monitoring, process control and modification, chip and wire bonding, packaging, test and installation into product. I also covered varactors, detectors, IMPATTs and TRAPATTs.

First,  Gunns are not diodes, but they became known as that pretty universally by mistake in the 60s. Secondly, they only display negative resistance above a certain voltage where RF also starts to be generated under the right conditions. Despite extremely tight measurement and QA I used to say 'every single device we make is different'. I never saw any attempt at combining the output of two devices and I would give it zero chance of working (even if only for a very short time under just the right conditions - mostly thermal). I know of several systems where we would dearly have liked to combine devices outputs for more power!

Before having all the above dropped into my hands, I was an oscillator designer and I can tell you that Gunns have to be in just the right place to achieve oscillation and matching to their (cavity) environment and other [detection or varactor] devices. Redesigning a 22GHz design to get a reasonable number of man-hours to make one work was a case of going back to fundamental design yet making it look the same on the outside.

Taking really cheap diecast oscillator cavities and turning them into transitions seems like making life overly difficult. Try using an established design.
--
73, Paul Evans G4BKI [VP9KF]

P.S. I was fortunate to have studied under Prof. Paul Butler at University of Warwick who 'wrote the book' on hot electron theory which matched John Gunn's achieved best-case Gunn performance, amongst other things.






Re: Gunns

Paul Evans W4/VP9KF
 

Well, I was the 2T [two terminal] Device Manager at Plessey Microwave, so I should be able to help you :-) My coverage was from wafer selection and test, epitaxy for all the devices we made, cleanroom design and monitoring, process control and modification, chip and wire bonding, packaging, test and installation into product. I also covered varactors, detectors, IMPATTs and TRAPATTs.

First, Gunns are not diodes, but they became known as that pretty universally by mistake in the 60s. Secondly, they only display negative resistance above a certain voltage where RF also starts to be generated under the right conditions. Despite extremely tight measurement and QA I used to say 'every single device we make is different'. I never saw any attempt at combining the output of two devices and I would give it zero chance of working (even if only for a very short time under just the right conditions - mostly thermal). I know of several systems where we would dearly have liked to combine devices outputs for more power!

Before having all the above dropped into my hands, I was an oscillator designer and I can tell you that Gunns have to be in just the right place to achieve oscillation and matching to their (cavity) environment and other [detection or varactor] devices. Redesigning a 22GHz design to get a reasonable number of man-hours to make one work was a case of going back to fundamental design yet making it look the same on the outside.

Taking really cheap diecast oscillator cavities and turning them into transitions seems like making life overly difficult. Try using an established design.
--
73, Paul Evans G4BKI [VP9KF]

P.S. I was fortunate to have studied under Prof. Paul Butler at University of Warwick who 'wrote the book' on hot electron theory which matched John Gunn's achieved best-case Gunn performance, amongst other things.


Re: SMA Adaptors

Neil Smith G4DBN
 

Hi Gareth, I've been making some WR90-SMA transitions milled from solid aluminium, with rounded corners and with the backshort distance and pin length set to give good RL over a few hundred MHz rather than mediocre RL over the 8-12 GHz range. I don't use a tuning screw, but I have to check the RL using a decent directional coupler and a waveguide dummy load.  My cavities have rounded corners, but the backshort distance isn't much affected by that.  I find 5.65 mm is about optimum to balance RL, bandwidth and ease of adjustment of the pin.  I ream the SMA mounting hole to 4.10 mm to take the 4.06 mm PTFE sleeve of the Radiall SMAs, but a cheap 4mm drill should work fine. 

It is a whole lot simpler to fit a fine tuning screw opposite the SMA rather than tuning by filing 0.05mm increments off the pin. My experiments were intended to find how reproducible the design would be and if a no-tune option is viable. Spoiler alert - it is WAY too much hassle unless you leave the PTFE on the pin, as otherwise it is too dependent on how you trim the PTFE back to the guide face. Newer versions will leave the PTFE in place and just machine the end off at a precise distance from the flange, then use a dielectric tuning screw so there are no corrosion or contact issues.

The other issue is that you don't know if you have taken too much off the pin until you are past the sweet spot, so I use a 0.2 mm brass shim under the SMA socket while I'm trimming the pin to length.  Then when I've gone too far, I can remove the shim and do a final adjustment.  Elegant and simple, but way too much work.


http://www.g4dbn.uk/?p=1570

If you want to re-use a gunnplexer, you might have to drill a new hole for the coax socket if it is < 5mm from the backshort, but if it is >6mm, you might be able to file a close-fitting plate from a bit of sheet metal the same as the body of the unit. You could then shove into the bottom of the guide to get the backshort distance to something near 5.5-6.0 mm and glue it in place with a drop of superglue.

Without machine tools, I'd find a bit of brass or copper guide and drill an SMA hole at 5.7 mm or so from the backshort, then solder on a backshort and flange. If you don't have a flange, use a bit of plate drilled and filed to fit. It would then need be aligned with a proper flange using a bit of wood cut to WR90 internal size as mandrel, drilled, then sanded flat using wet/dry paper on a sheet of glass, using WD40 or light oil as lube. I'm assuming 1.27 mm pin size. Fatter pins generally widen the bandwidth, but are fiddly to make.

You could use 22mm water pipe with an end cap soldered on, then file a flat on the side and solder on a 2-hole SMA.  Backshort distance in 22mm pipe should work out around 6.4mm, but I'd do it 7mm and tap an M3 hole in the middle of the cap, then tune that and the pin length to get a decent match. You could force the other end into a rectangular flange or just leave it round, depending on what want to use as a feedhorn.

If you want to make a rectangular transition but have no waveguide, you should be able to anneal a bit or copper pipe and file a bit of aluminium bar to WR90 internal size, then form it into a tapered and rounded mandrel, and use that to force the round tube to become rectangular.

Beware of working out how much to take off the pin to bring it into tune, the relationship is non-linear and it is much too easy to go too far.

If you imagine the pin size and backshort distance behave rather like tuning an L-match. There are infinite pairs of matches within certain limits.  The trick is to get the Q to a reasonable value

Have a look at the W1GHZ papers:

http://www.w1ghz.org/QEX/Rectangular_Waveguide_to_Coax_Transition_Design.pdf

http://www.w1ghz.org/QEX/circular_wg.pdf

and his Antenna Book online: http://www.w1ghz.org/antbook/contents.htm

Neil G4DBN

(Note: I am currently tied up 100% on 24/7 carer duty looking after my wife who has terminal cancer, so only answering emails or twitter messages every few days when a respite carer visits. Life and projects are mostly on hold but I'm doing stuff sporadically)



Re: August RadCom GHz bands input

Barry Chambers
 

Hi John

Hopefully I will be able to do some more 30THz Moon noise measurements in a week or so (full Moon). I have now properly focussed up my mirror dish which should make quite a difference.

I have heard nothing more from Giles about using his imagers to copy 30THz cw but hope he does try it and report his findings - that's how we all make progres and increase our knowledge

I may try putting a detector with more than one pixel in one of my dishes - only 8 x 8 but it will be interesting to see what the image looks like and whether it offers any advantages - I suspect not because there is no way to combine the signal outputs from each pixel and each pixel in an array will be smaller in area than one large pixel as in the MLX90614 which I am currently using.  .

73 Barry, G8AGN


On 09/06/2021 09:55, John Worsnop wrote:
Hi Folks,
If anyone has any activity news, DX reports or Tech Snippets for the RadCom Column, can you get them to me by this Friday please?  Reports on the recent UKACs welcome, especially if you worked anything out of the ordinary. Reports from newly active stations on 1.3GHz and up particularly welcomed. Any mode....CW, digi, SSB, TV. You name it' I'll cover it! 
Is anyone doing FT8 on 23cms?? If so, does it work? where are you congregating?Send me reports and details.

We HAVE to be seen to be using these bands. Don't keep it to yourself!

73
John

-- 
73
Barry, G8AGN


Gunns

Chris Bartram G4DGU
 

Hello Dave,

Being negative resistance devices, Gunn oscillator cavity design isn't necessarily intuitive, and putting two into a cavity will probably lead to unexpected results! The guy from Virginia Diodes was probably correct ...

Chris

G4DGU


SMA Adaptors

Chris Bartram G4DGU
 

Hello Gareth,

I agree with Dave that it's quite unlikely that simply replacing a Gunn with an SMA probe will work properly. This is a question of impedance matching. You shouldn't need to use a screw tuner to get it to work reliably. I can't give you a recipe for a WG16 to SMA adaptor, as I haven't used WG16 for many years: I standardised on WG17 for my own 10GHz systems, and was fortunate enough to come across some lab.standard adaptors. However there are good amateur designs out there, and I'm sure somebody from this group will direct you to them.

73

Chris G4DGU


August RadCom GHz bands input

John Worsnop
 

Hi Folks,
If anyone has any activity news, DX reports or Tech Snippets for the RadCom Column, can you get them to me by this Friday please?  Reports on the recent UKACs welcome, especially if you worked anything out of the ordinary. Reports from newly active stations on 1.3GHz and up particularly welcomed. Any mode....CW, digi, SSB, TV. You name it' I'll cover it! 
Is anyone doing FT8 on 23cms?? If so, does it work? where are you congregating?Send me reports and details.

We HAVE to be seen to be using these bands. Don't keep it to yourself!

73
John


Re: 10GHz SMA to WG16

Wilko
 

I would personally go for the "brass route". I have
built a number of these sma-wg transitions. Measurements have shown that they are not at all bad. I lack equipment to measure things like
S11 at this frequency so I had to work based on mechanical dimensions and hope for the best.

Obviously the measurement results led to some smugness on my part :-)

Wilko
PA1WBU


Re: LA2T9Q ''6GHz' amplifier spec?

Keith Le Boutillier
 

Gareth

 

Take a look at https://www.ppauctions.com/lot/157880/lot-84?auction_filters=cGFnZT0z

 

And see Lot 84

 

It covers IJ bands at 400 watts its listed at £10.00 may be worth a look

 

73 Keith GU6EFB

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Gareth G4XAT via groups.io
Sent: 09 June 2021 08:47
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] LA2T9Q ''6GHz' amplifier spec?

 

This device is inside some cheap ALiExpress amp boards (under a tin can screen LA2T9Q). Unable to find any spec on it but wondering if it has ANY gain left at 10GHz. Very hopeful I know, but trying to raise a mW for the weekend from a Pluto 5th harmonic.
They certainly work to some degree on 5.7GHz where I got improved signals by using one in the RX chain, but other than looking at the received signal via a LNB and SDR I have no means at present of measuring any 'gain'.
The boards are typical eBay 'DC to Daylight' SMA in/out with 5vdc in, so it may be possible to swap in something of known capability at 10GHz.
Suggestions very welcome.

Gareth


Re: N plug solder for semi rigid

Keith Le Boutillier
 

Good morning all

 

See www.coax-connectors.com

 

They are UK based and have a full range of full spec connectors. I have always found them very helpful, just a happy customer

 

73 Keith GU6EFB

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of alwyn.seeds1
Sent: 09 June 2021 08:52
To: UK Microwaves groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] N plug solder for semi rigid

 

Dear Ben,

 

This is now a bit of a challenge.

 

Tyco moved their production to China and the designs are different from the ex-Greenpar ones.

 

There are many distributors of N connectors who are selling parts with poor design/poor tolerances- I have measured these and they show worse return loss than what used to be available.

 

Huber and Suhner are good, also Telegartner as a lower cost option, if they meet your spec.

 

Radiall have moved the production of a lot of their N connectors to China. I have measured some samples of these and they are within spec.

 

Cinch have introduced some low spec. ranges, check spec. carefully.

 

Likewise Amphenol.

 

So, I think you now have to check spec. very carefully, and do n’t be surprised if a connector that meets the MIL spec. to 12 GHz or 18 GHz is quite pricey.

 

So far as I know, there is no longer any manufacture of N connectors in the UK.

 

Regards,

 

Alwyn G8DOH

 

 

_____________________________________________________

 

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.

_____________________________________________________

 


Re: N plug solder for semi rigid

alwyn.seeds1
 

Dear Ben,

This is now a bit of a challenge.

Tyco moved their production to China and the designs are different from the ex-Greenpar ones.

There are many distributors of N connectors who are selling parts with poor design/poor tolerances- I have measured these and they show worse return loss than what used to be available.

Huber and Suhner are good, also Telegartner as a lower cost option, if they meet your spec.

Radiall have moved the production of a lot of their N connectors to China. I have measured some samples of these and they are within spec.

Cinch have introduced some low spec. ranges, check spec. carefully.

Likewise Amphenol.

So, I think you now have to check spec. very carefully, and do n’t be surprised if a connector that meets the MIL spec. to 12 GHz or 18 GHz is quite pricey.

So far as I know, there is no longer any manufacture of N connectors in the UK.

Regards,

Alwyn G8DOH


_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Re: LA2T9Q ''6GHz' amplifier spec?

geoffrey pike
 

Almost certainly it will be not very good at 10 GHz but how many mWs are you thinking of needing at 10 GHz?
Have you looked at the Franco SU-02 board
cheers
Geoff
GI0GDP

On Wednesday, 9 June 2021, 07:52:27 BST, Gareth G4XAT via groups.io <g4xat@...> wrote:


This device is inside some cheap ALiExpress amp boards (under a tin can screen LA2T9Q). Unable to find any spec on it but wondering if it has ANY gain left at 10GHz. Very hopeful I know, but trying to raise a mW for the weekend from a Pluto 5th harmonic.
They certainly work to some degree on 5.7GHz where I got improved signals by using one in the RX chain, but other than looking at the received signal via a LNB and SDR I have no means at present of measuring any 'gain'.
The boards are typical eBay 'DC to Daylight' SMA in/out with 5vdc in, so it may be possible to swap in something of known capability at 10GHz.
Suggestions very welcome.

Gareth

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