Date   

Re: X Band ( 8-8.6 ghz) LNA wanted

Andy
 

On 21/11/2020 14:09, Keith wrote:
Just wondering if anyone has, or can direct me to, an LNA that covers 8-8.6 ghz specifically.
Used or new but preferably without sacrificing my first born child :)
The rest of my 8ghz gear is coming together nicely, but a band specific LNA would be a real bonus.
Mr Google isn't helping in my searches .
On the off chance ;)
Cheers
Keith VK6KB/VK6EME
Maybe some guys in Puerto Rico will have some kit for sale :-(

73
Andy


Re: Optimum tone freq for detecting a weak

Bo, OZ2M
 

Perhaps Desi Lydic can help with the numbers: https://www.youtube.com/watch?v=bBpYG7qBBqs


Re: about Crystal manufacturers

Clint Sharp <cjaysharp@...>
 

FWIW, google translate doesn't do a great job of the pdf files available on axtal.com but it does give enough that you can work it out. 


On Sat, 21 Nov 2020, 11:09 Ferdinand DC8EC, <dc8ec@...> wrote:
Hello Francois,

you forgot axtal.com. Lots of technical information and the "quartz cookbook" to download.

Ferdinand DC8EC


File /Quartz Crystal manufacturers/quartz_story.htm uploaded #file-notice

UKMicrowaves@groups.io Notification <noreply@...>
 

The following files have been uploaded to the Files area of the UKMicrowaves@groups.io group.

By: F1CHF

Description:
updated with your inputs ! tks


X Band LNA Wanted

Barry VE4MA
 

Gidday Keith

DownEast Microwave in the USA has them for $150 see model L4-2ULNA

Best 73
Barry VE4MA




Re: Optimum tone freq for detecting a weak

Neil Smith G4DBN
 

There is a whole level of nutjob action on Youtube where they publish copies of music with A set to 432 Hz instead of 440 cos it does Healing and is more in tune with the Universe and stuff.  All about harmonics of Schumann resonances.

Good grief.

Except it isn't.  It's all because Verdi didn't like singers being divas about high notes. Allegedly.

There are even apps that will do the 440->432 conversion.

Gentle pee-extraction of the nuttiness by this guy.... https://www.youtube.com/watch?v=EKTZ151yLnk

Neil G4DBN

On 21/11/2020 13:57, Andy G4JNT wrote:

I posed the same question to an ex-military comms intercept chappess.   Her first comment was that:
 "you're all a bunch of deaf old f__rts who can only ever hear low tones" (they're a rude lot, ex military types) then commented that there were considered to be two 'magic frequencies', but wouldn't say initially what they were.   Today she came back with:
"432Hz is favoured by many in the healing game, occasionally there are them that think 528Hz works better".   

Which has got nothing to do with comms intercept work, and seems more about meditation and cult stuff, but I tried listening to those tone frequencies, including buried in noise.  And she's right.  They do sound 'nice'  and quite detectable.  They also happen to be in the ratio 11/9.  So just for the fun of it, there are now eight user-selectable tones in my gizmo, in the ratio 1.2222222   starting 432, 528, 645 etc up to 1760Hz.   Details will be published in due course (writing it up now, hopefully in time for Scatterpoint)




X Band ( 8-8.6 ghz) LNA wanted

Keith
 

Just wondering if anyone has, or can direct me to, an LNA that covers 8-8.6 ghz specifically.
Used or new but preferably without sacrificing my first born child :)
The rest of my 8ghz gear is coming together nicely, but a band specific LNA would be a real bonus.
Mr Google isn't helping in my searches .
On the off chance ;)
Cheers
Keith VK6KB/VK6EME


Re: Optimum tone freq for detecting a weak

Andy G4JNT
 


I posed the same question to an ex-military comms intercept chappess.   Her first comment was that:
 "you're all a bunch of deaf old f__rts who can only ever hear low tones" (they're a rude lot, ex military types) then commented that there were considered to be two 'magic frequencies', but wouldn't say initially what they were.   Today she came back with:
"432Hz is favoured by many in the healing game, occasionally there are them that think 528Hz works better".   

Which has got nothing to do with comms intercept work, and seems more about meditation and cult stuff, but I tried listening to those tone frequencies, including buried in noise.  And she's right.  They do sound 'nice'  and quite detectable.  They also happen to be in the ratio 11/9.  So just for the fun of it, there are now eight user-selectable tones in my gizmo, in the ratio 1.2222222   starting 432, 528, 645 etc up to 1760Hz.   Details will be published in due course (writing it up now, hopefully in time for Scatterpoint)




Quality control

militaryoperator
 

Someones QC needs looking at!

DSCF3371.JPG


Re: about Crystal manufacturers

Ferdinand DC8EC
 

Hello Francois,

you forgot axtal.com. Lots of technical information and the "quartz cookbook" to download.

Ferdinand DC8EC


Re: Optimum tone freq for detecting a weak

Bo, OZ2M
 

Hello

My empirical findings are that most people prefer somewhere between 600 Hz to 700 Hz. Some below 600 Hz and very few above 700 Hz. I haven't got a clue why 800 Hz ever came into the picture since not many listen to CW at 800 Hz.

Attached is a single slide from one of my presentations at the 2018 RSGB Convention showing the sensitivity of the ear vs frequency and age.

Bo


Re: 5th Overtone Crystals

Adrian G4UVZ
 

Also Krystaly.cz 


about Crystal manufacturers

F1CHF
 

I have uploaded in the files area a list of manufacturers
also on my web site
 
if you have any inputs, don't hesitate 'sorry it is in French ... oupps !
 
Francois F1CHF


File /Quartz Crystal manufacturers/quartz_story.htm uploaded #file-notice

UKMicrowaves@groups.io Notification <noreply@...>
 

The following files have been uploaded to the Files area of the UKMicrowaves@groups.io group.

By: F1CHF

Description:
quartz manufacturers (in French ... sorry)


Re: UK / EU Group Purchase of Si Radar Devices

Dave G8KHU
 

Hi Neil

Ive registered you interest. Last I heard (again August this year) only a few pre production 130 GHz and 300 GHz chips were available - at eye watering prices. I will check again though if this purchase goes ahead.

73 Dave G8KHU


Re: 5th Overtone Crystals

Adrian G4UVZ
 

Thanks for the information..I have put a request into ESKA.DK  and await a response

Adrian


Re: 5th Overtone Crystals

ian hope (2E0IJH)
 

For anyone that needs a LO,I have a spare Digi-LO that has come out of Q5 Transverter it's currently on 116mhz but can be changed, http://q5signal.com/index.php?route=product/product&product_id=67, This one has the higher spec TCXO fitted.
 
Ian
M5IJH

 
 
Sent: Friday, November 20, 2020 at 1:09 PM
From: "mike G6TRM via groups.io" <mike.bryant@...>
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] 5th Overtone Crystals
Hi Adrian,
Have you tried.. 1)Eisch-electronic.com, or   2) Krystaly.cz
 
rgds
 
Mike G6TRM
----- Original Message -----
Sent: Friday, November 20, 2020 12:34 PM
Subject: [UKMicrowaves] 5th Overtone Crystals
 
As part of the GB3KBQ refurb  I need to purchase a 108.0090622 MHz crystal

I have to admit it is a long time since I bought a crystal ..however I had not realised that things had changed so much in the crystal supply industry.

I was prepared for a hike in crystal pricing ..however the industry now appears to be geared to minimum  quantities.

The Best quote I have to date is a minimum of 3 crystals at £18.51 each plus VAT 
The Second best quote is 5 units at £35.69 each  again plus VAT !!
Both quotes are from UK suppliers.

I would be pleased to hear if anyone can supply details of a supplier with a better pricing structure!


Re: Optimum tone freq for detecting a weak

DAVID G4ASR
 

For very, very weak signals in the noise its got to be around 500Hz for me. 

I can then filter out the noise in my brain and just listen only to the low tone which appears centrally about 5cm above my nose.

It takes a few seconds to sync up. Aircraft scatter messes it up somewhat but signals are louder and my brain filter opens up then,

I dont know what others do but for very weak cw signals on the microwave bands I open up the filter bw to 1800Hz, sometimes a bit wider. 

Wish I had my adjustable SG Brown headphones now. 

73 David G4ASR
  

 


Re: UK / EU Group Purchase of Si Radar Devices

Neil Smith G4DBN
 

Hi Dave, I'd like two of the TRX_120_001 chips please, I want to have a play with a flexure-mounted translation stage and/or lenses for tx/rx changeover with the patch-equipped chips, using boards based on the VK5 approach. I have a huge pile of other stuff to finish first, but might as well have the chips in stock.

I've just finished another batch of the free-rotating VK3CV to UG-387/U flanged couplers and W2IMUs and hopefully I'll get a batch of Pickett-Potters done over the weekend. I've also made up a copying attachment so I can make very precise Cassegrain hyperbolic subreflectors for those Edmunds f/d 0.25 dishes, but I need to get more heatspreaders and WR90-SMA couplers made and shipped before I make up the Cassegrains. I don't have time to go to work any more, it eats into radio/machining playtime too much.

In the dark reaches of the night when I can't run the machine shop for fear of waking the village, I've hacked up the modulation source code in WSJT-X to send the transmit tone sequences to a UDP listener, which then generates control words for a DDS at submultiples of the various mode tone spacings.  Those can then be multiplied up or used as the reference for an SHF PLL to get the correct spacing at a final frequency.  The DDS I am using is not ideal, but I have an AD9912 board on the way, so fingers crossed, I might be able to get something sorted to try by mid-Dec.

I guess there is no sign of the newer chips being available yet is there?

Neil G4DBN

On 20/11/2020 13:51, Dave G8KHU wrote:
Hi All

For information the last pricing I had from Silicon Radar (August 2020) for low quantities was as follows:
TRX_120_001     35,47 Euro Each
TRA_120_002     22,40 Euro Each
LNA_024_004     10,50 Euro Each
TRX_024_006     10,47 Euro Each
TRX_024_007     10,47 Euro Each
These prices are EX VAT (19% in Germany) and ex Carriage.
With a reasonable amount of interest I would hoe that we could get the amortised carriage from SI Radar to the UK don to <5 Euro per device. Shipping from me to the UK is £2-£3 and to the EU <£10 per shipment.

I hope this helps if you are interested.


Re: AVANTEK Amplifier Module

Gordon REASON
 

Hi Doug .........

just looked at the pictures !

Very similar to what I worked with on many occasions .

They are individual RF amplifier modules .

The fets would be class A , and each fet having its own source bias resistor .

The 7th one is a voltage regulator , which woulf provide a stable + bias of 5 to 8 volts .

The regulator is a normal three terminal regulator , in Chip IC form , with the two chip capacitors of 1uF minimum on the same but of ceramic substrate .

The dc supply, input ,  to the regulator will be via the feedthrough , seen in the hole .

The 8th module is a temperate compensation , PIN Diode module , and again the current fed via the Feedthrough .

My picture definition and eyes are'nt too good , but I cannot see anything out of order , which is good .

Normal faults , to be seen , are an rf overload , of the input FETs , characterised by a sooty Plasma deposit arount the input fets , seen more clearly with a microscope , one of those USB , PC microscopes would be usefull !

Overload of the Chip Voltage regulator , again  best seen with a microscope , a melting of the top surface of the chip .

A microscope visual , of each ceramic module , with a side angled light , where you may see a crack across the substrate ......... imagine that the track to the gate is broken , then no gate control of the Fet , so full Idss current flows ......

This , for your excess current flow , would be more likely to be one of the modules nearer to the output .

If you can see a crack through a track , running a smoothed needle across the crack , to smear the gold together can restore correct operation .


So , get a dmm with one lead to the metal of the amp, ground .

Take a needle probe from the positive of the Dmm .

Set to the lowest Ohms range .

with no DC supply to the amp !!! connect ground to the sma connector ?

With the needle probe , probe to end of the chip capacitor(s)  , on the 7th module  .

Two of the ends should be ground .........

Each of the other ends , one should be a low resistance , as you are reading to fet circuit resistance , so expect cica 10 ohms .

the other end , from dc input , but there may be a second regulator hidden in the black epoxy , should be a much higher resistance of  > 2000 ohms ............

if that reading is low , then thats where the problem is ?



On 03 November 2020 at 12:33 DougF VK4OE <uwaves@...> wrote:

Greetings to all readers, and thanks for the various suggestions received on this subject.

I thought that a little update is in order following some purpose-driven investigations which I have made on this amplifier module today.

Firstly, yes, the top cover was held in place by a continuous seam of aluminium welding around the perimeter.  It was easy with a vertical milling machine to carefully remove enough material (only 1.2 mm) in order to be able to see the horizontal dividing line between two metal components all the way around.  After that, the cover with its complicated fitted extensions down into the "microwave electronics space" (most likely structures which prevent spurious oscillations) could easily be lifted free.

One of the accompanying pictures shows the amount of glass-substrate microwave circuitry with all its wire bonding, which was revealed when the top cover was removed.  On initial inspection, nothing seemed glaringly wrong or out of place there.

Next, the bottom plate with all of its screws removed did "pop free" this time with less effort  than I had been using the other day, revealing that it had been some semi-hard silicone cavity filler material which had been preventing detachment of the plate.  A couple of days under less tension with the screws removed may have facilitated it 'letting go'.

As you'll see from the other attached picture, what the bottom plate had been covering is just the DC input componentry, with two DC feed-through-paths leading from this little 'alcove' to the microwave electronics on the top side.  As already mentioned, the carefully milled hole or space there is filled with some sort of semi-hard silicone filler material which may be able to be removed with care using a sharp blade.

Although I have not yet measured what's going on DC-wise there, it is quite possible that the small tantalum capacitor that's present has gone short circuit taking the series diode with it.  Wouldn't it be very nice if the failure that has occurred is as simple as that?!  But that doesn't explain the residual 2 or 3 mA of current....  If those DC feed components test good, then the fault is likely to be in the impossible-to-work-on microwave electronics, leading to the amplifier being 'written off' with the only benefit from having investigated is to reveal things about these modules which may help others at a later time.

It may be a couple more days before I get back to these investigations, so I thought this update may be of interest to numbers of readers of this thread.  At least my questions about internal construction of AVANTEK amplifier modules of this vintage have been answered.

Cheers and best wishes,

--Doug Friend, VK4OE.

On 02/11/2020 1:12 am, Gordon REASON via groups.io wrote:

You need to know how the inside is milled , but I removed some lids by , using a drill bit with a stop on it , to prevent the drill bit going through and doing damage to internal circuitry .

A connector from a chocholate block connector works well .

Then you can drill the lid , untill you create a hole .

Then very carefully , insert a screwdriver , and apply pressure and a click will indicate that the lid seal has broken .

The weld does'nt go very deep ...........it's a weatherproof seal .

It's best of course , to know the internal milling , then you can drill the lid , with a 2.5 mm hole , tap it with a 3mm tap .

Insert a 3 mm screw , and that will lift the lid off , and that done the lid will probably peel off ....

And as Paul suggested , use a vaccumm to take any swarf away .

I used a scalpel , sometimes to scrape the aluminium  ? ,  flat , for rewelding .. saved hours avoiding milling flat ........still waiting for my medal.


 


 

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