Author Topic: EEVblog #306 - Jim Williams Pulse Generator (Read 295379 times)

carpin · « **Reply #100 on:** August 08, 2012, 09:53:40 pm »

Try ebay

FRT · « **Reply #101 on:** August 28, 2012, 09:40:53 pm »

Quote from: KTP on August 02, 2012, 11:15:39 pm

Ok, so they aren't *that* far apart...but it is almost 10% off and makes me wonder even how much shorter I could measure if I had a circuit capable of 200ps rise time. I think you need the flat top.

I totally agree, it does need the flat top, not only so the scope can catch up (because a slow scope with a fast edge won't get to the high logic level fast enough to really know where 10/90 or even 20/80 is) but also so you can see how much overshoot and ringing is created by digital brick wall filtering. A short pulse will mask this behaviour.

I'd like to get a pulse generator that has a fast edge, but a longer pulse width so the scopes behaviour and settling can be seen.

G7PSK · « **Reply #102 on:** September 04, 2012, 08:32:32 pm »

Saw this on ebay today.

http://www.ebay.co.uk/itm/390440463608?_trksid=p5197.c0.m619#ht_4348wt_1322

Pulse generator from type 42 Destroyer.

prenato · « **Reply #103 on:** September 19, 2012, 04:58:35 pm »

Hi Free-electron

Are you still selling these on ebay? I would definitely be interested...

Thanks,

Paulo

free_electron · « **Reply #104 on:** September 19, 2012, 07:20:19 pm »

i'm back from vacation. will prepare the kits over the weekend and throw them on ebay.

free_electron · « **Reply #105 on:** October 10, 2012, 01:21:46 am »

Finally got some time to finish mine and 'hand select' the transistors for the kits. ( i ran them on the curve tracer and selected the ones that avalanched at around 40 volts. there is notable difference between the 2N2369 and 2N2369A and then manufacturers...
the ones from ST avalanche much higher .... i found a bunc of motoroils at the local junk dealer. these work fine.

Ran the pulser into a 7GHz analog bandwidth scope ( see attached image )

210 pS rise time on an almost 10 Vpp signal ( 10% to 90% ) so 210pS to do 8 volts. That's a -VERY- fast signal. And it may be thelimit of the scope .. (7GHz analog bandwidth ,injected diectly into the 50 ohm SMA port ( this scope has SMA inputs ))

So , i will assemble and package kits today and tomorrow and then they will appear on ebay. i will call the item JWPULSER so search for that starting Thursday. I only charge the cost of the parts. Comes with a case , SMA connector ( no sma-bnc adaptor ) and you get two of the transistors.

HackedFridgeMagnet · « **Reply #106 on:** October 10, 2012, 03:53:57 am »

Well done!

Looking forward to getting one, hope I'm fast enough.

notsob · « **Reply #107 on:** October 10, 2012, 05:01:30 am »

I put my name in for one when you 1st started - so I'll be looking for one also

Great work

prenato · « **Reply #108 on:** October 11, 2012, 05:22:36 am »

Great job! Keeping an eye on eBay now...

free_electron · « **Reply #109 on:** October 11, 2012, 05:00:55 pm »

i will post them tonight (US - west coast time )

robrenz · « **Reply #110 on:** October 11, 2012, 05:50:15 pm »

I already hit the Ebay search button 500 times since your previous post

free_electron · « **Reply #111 on:** October 12, 2012, 04:40:59 am »

and rob_renz takes the crown

i'll throw in that low noise cable i promised you. it's been laying in my care ofr 3 months now... just need to get to the darn post office.

kits will ship on monday ( if paid ).

Right now there is 5 on ebay ( minus one ).

robrenz · « **Reply #112 on:** October 12, 2012, 04:52:41 am »

Thanks free_electron, I used the JWPULSER search term and it worked and I payed. but if I go back and search that now it does not find it. You might want to make sure the listing is still good. I think it was listed as a single item not multiple.

free_electron · « **Reply #113 on:** October 12, 2012, 05:45:01 am »

I got the payment. I'll ship yours tomorrow. There's a surprise in there as well. you'll see :p

hmm strange. i see them as 'listed' but ebay search doesnt find them. this whole ebay thing is weird to me. i can never figure it out. just finding how to add international shipping took me an hour.

here are the other 4 listings :

-gone-

http://www.ebay.com/itm/150922538076?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

http://www.ebay.com/itm/150922538184?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

-gone-

I will list 2 more tomorrow. after that i am out of boards ...

I can always do another run at itead. But then we need to organize it more so i can buy larger quantity and get price down.

HackedFridgeMagnet · « **Reply #114 on:** October 12, 2012, 05:49:41 am »

I cant find them, are they gone?

notsob · « **Reply #115 on:** October 12, 2012, 05:49:54 am »

I havent been able to get a result for jwpulser search

free_electron · « **Reply #116 on:** October 12, 2012, 05:51:20 am »

use th elinks above. for some reason ebay search doesnt find them... the direct links take you there.

notsob · « **Reply #117 on:** October 12, 2012, 05:55:09 am »

Thank you fe appreciate your efforts

free_electron · « **Reply #118 on:** October 12, 2012, 05:57:25 am »

notsob and hackedfridgemagnet payment received. those will leave tomorrow as well

carpin · « **Reply #119 on:** October 12, 2012, 07:30:04 am »

Quote from: free_electron on October 12, 2012, 05:45:01 am

I can always do another run at itead. But then we need to organize it more so i can buy larger quantity and get price down.

I was sleeping

It would be great if you organize a groupsbuy, and the siliconvalleygarage JWpulser as a kit.
And is a BNC male bulkhead connector possible?

Thanks

HackedFridgeMagnet · « **Reply #120 on:** October 12, 2012, 07:41:10 am »

there is one still left carpin, 3rd down

carpin · « **Reply #121 on:** October 12, 2012, 07:51:45 am »

Thanks HackedFridgeMagnet
The 3rd down is a auction, Time left: 2d 20h
If I bid on the jwpulser, I always lose

HackedFridgeMagnet · « **Reply #122 on:** October 12, 2012, 08:08:50 am »

What happens if you press buy it now?
That's what I did.

carpin · « **Reply #123 on:** October 12, 2012, 08:21:03 am »

Thanks again HackedFridgeMagnet
I didn't see the buy it now option.

free_electron can you sign my board with your signature?

Thanks

free_electron · « **Reply #124 on:** October 12, 2012, 07:50:04 pm »

off to the post office. they leave in an hour ...


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Author Topic: EEVblog #306 - Jim Williams Pulse Generator (Read 295379 times)

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