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Gunnplexer at 10GHz

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Not sure how old the article in that link is...
Unfortunately, for some years, Microwave Assoc no longer exist they were bought out by Tyco

you may find the occasional amateur radio operator with one lying around. My ones are still tied up in my ATV transmitters

maira_289 Are you an amateur radio operator ? what was your plans for the Gunnplexer ?
There are easier ways to go on 10GHz WBFM and I could help you there :)
namely still using a Gunn Osc for TX but a TVRO LNC for receive

Dave
VK2TDN
 
Thanks for your kind response.
Actually i want to make a linear FMCW radar as my research project, i am a Masters student. I have been trying to get a gunnplexer as it has all the things in it (VCO, Coupler, Circulator and mixer) making my hardware simpler. Can you tell any link that still deals with Gunnplexers sale. I have tried several but mostly either don't reply or they have stopped selling them now.

is there any easier way that i get VCO coupler and circulator if i don't go for a gunnplexer
maira
 
I think you will find next to impossible to buy commercially these days
They were all the rage in the 70's to 90's as they were an easy way to get good power at 10 to 100 mW odd at almost any microwave freq.
As technologies improved through the 90's and into the 2000's everything switched to on PCB semiconductor oscillators, GPS locked etc and were extremely stable.

for a radar, Im not sore what sort of distances you were looking at, but the very low power out of a Gunn osc even with a 30dB gain dish is still very low TX power.
Klystrons capable of being pulsed to produce very hi peaked outputs may be more what you need
I'm not sure how well Gunn Osc's can handle significant pulsed drive voltages, maybe some google searching mite help

cheers
Dave
 
Do what my local CBers used to do. Go down to your local shopping center and rip one off the automatic doors late at night :)

Ok.. they are not hard to find on the surplus market and they are cheap so you don't need to steal them. Visit any alarm installer and they will probably give you a box of old units for a case of beer. If you're really hard pressed, go down to your local pawn broker and buy up a box of the cheapest and oldest radar detectors you can find and you will have plenty of Gunn Diodes and detector diodes to play with.

Plenty of Gunn heads on ebay. $10-$30 is what you should pay for them.
270897383930 270842101053 260956100537 and so on http://www.ebay.com/sch/Consumer-El...?_nkw=X-band&_catref=1&_trksid=p3286.c0.m1538


You can also rip DRO's out of old satellite LNCs.
Klystrons are a bit of a pain in the bum to use. Gunn Diodes can be pulsed in the same manner as klystrons, but there is no need to do that.
Using code spreading sequences is a much better way to get better radar performance out of a 20mW Gunn Diode.

A Gunnplexer (tm) is a specific type of gunn head.
My webshots page is getting a workout tonight again Dave...
http://home-and-garden.webshots.com/photo/2817151550048941318Vcrkbm

That's one of the hotwheels toy radar guns that I bought from K-Mart.
In true Tim Allen style I said..."This thing needs MORE POWER... so I rewired it ! Put a 300mW gunn diode head into that bugger ! Now it starts fires at 100 yards !" :D Actually, it can get speed reading off cars from about 2km away. I tested it on the Bourke Rd a few years ago.
 
My webshots page is getting a workout tonight again Dave...
http://home-and-garden.webshots.com/...48941318Vcrkbm

That's one of the hotwheels toy radar guns that I bought from K-Mart.
In true Tim Allen style I said..."This thing needs MORE POWER... so I rewired it ! Put a 300mW gunn diode head into that bugger ! Now it starts fires at 100 yards !" Actually, it can get speed reading off cars from about 2km away. I tested it on the Bourke Rd a few years ago.


I dunno mate what ARE we gonna do with you :rolleyes: haha
Gosh the best Gunn TX I have here is ~ 120mW

Take care buddy
Dave
 
I scored some high power diodes from ebay many years ago. They were dirt cheap because nobody wanted just the diodes.
20mW is standard and even they kick arse. Des Cliff got my attention when he ran 10mW over a 250km path.

They really don't need more power, a better low noise front end works MUCH better than the poor old diode mixer.
 
They really don't need more power, a better low noise front end works MUCH better than the poor old diode mixer.

yes agreed there ... I gave up on the Gunnplexer idea, just used the Gunn for TX only and used a satellite LNC instead for receive instead, so much better!!

Des Cliff ... is he the VK5 guy ? if so that's where my 120mW unit came from

Dave
 
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