EEVblog #306 - Jim Williams Pulse Generator

[free_electron]

Wow, this seems to be picking up again...
I need to look into this. I was planning on doing another run by the end of the year, but that's not going to happen . I am too busy.

I have secured a supply of the transistors though. I have a few thousand of em now. All new old stock made by signetics. They avalanche nicely.

I will place an order for a batch of boards.
I am assuming everybody can easily get standard passive smd parts in his/ her country

I would do the kit as follows
Pcb
The linear boost chip
The switch
The diodes and high voltage caps
The battery clip
Two of the transistors , so you have a spare
The angled sma connector
The 50 ohm output resistor (we need a non inductive here)
The case

Essentially the parts that may be hard to get locally.

Then again.. The remainder is 4 resistors and 2 caps...

Or i could simply do pcb,transistor,case.

The problem is always the cost of international shipping. Flatrate boxes have gotten expensive,
That turns some people down... And the customs paperwork and other blabla...

I need to find a better way.

[alank2]

Thank you free electron!  I will be happy to get whatever kit you get together.  I don't mind building it.  Let me know when you have the pcbs and they are available!

[H.O]

Yep, me too if possible!
No problems with getting standard parts.

Thanks!

[VintageTekFan]

I would also be interested, in kit form.

[FTM777]

One set of whatever you produce for me too please.  I can source standard components.
Nick

[kvitekp]

pcb only, pcb + avalanche transistors, full kit -- anything works for me here.

Packaging kits is terribly time consuming. DigiKey used to do kitting/packaging but the price was a little too high to make it attractive for DIY kit suppliers. Hiring someone here in Bay Area to do kitting is cost prohibitive. So for the time being pcb + rare parts + case and DigiKey/Mouser BOM seems like the way to go.

Filling intl customs forms is another hassle. I'm trying to get myself an old dot matrix or daisy wheel printer to try printing those custom forms. Weird Stuff has some, but none were functional last time I checked.

[G7PSK]

Get the boards sent from China, for some reason they don't seem to have customs problems, guess they just ignore them like every thing else.

[oe6kyg]

i have no problems to get custom parts
and no problems with higher shippingcosts

[JohnB]

Anything works for me as well.

Happy Thanksgiving to those in the US

[AndersAnd]

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.

So you're saying that 2N2369A is better suited than 2N2369 non-A, or is it the other way around?

And Motorola is better suited than ST?

Any manufacturing dates working better than others?

I found a source selling various NOS (new old stock) 2N2369 and 2N2369A from different manufacturers like Motorola, ST, NEC, Philips and Microsemi I think. Would Motorola be the best suited of these? Anyone tested other manufactures than Motorola and ST?

[BravoV]

Remember, at LT app note, even Jim Williams had to sort out from many samples until he found the one that avalanched nicely.

If they're cheap, I would buy few each from every different brands.

[free_electron]

i'm stocked up on 2n2369's. i got a few thousand now

i'm out for now. Battling a very nasty MRSA infection.... all because of a tiny little scratch on my back.

There won't be anything coming before january.

[all_repair]

Always wanted one, but not sure you want to be troubled again to do that.  But I don't check the forum on a regular basis, likely shall miss the boat again.

[robdot]

Hi free_electron, how are you going ?
Cheers,
Rob.

[jboard146]

+1 kit for me

[alank2]

Hi free_electron, how are you going ?
Cheers,
Rob.

+1 I hope you are feeling better soon.

[GreyWoolfe]

Free_electron, get better soon and put me down for one.  Many thanks.

[Fsck]

+1 to the kit too.

[apelly]

Another +1

Hope you're well again.

[MrAureliusR]

@free_electron

Hope you're doing well. A good friend of mine had an MRSA infection in her leg, and she lost most of the muscles in one leg, and parts of her other leg as well. VERY brutal bacteria... unfortunately it can spread through bare skin to bare skin contact!!!

Really hope you're doing better...

Also, wishing for a kit I will be sure to check back often, I've been keeping an eye on your website as well.

On an aside to everyone, I've started a new electronics site @ http://frozenelectronics.com ... I'm very excited and look forward to all the work associated with a video blog / writing blog.

[idpromnut]

@free_electron:

I hope the new year finds you in better health!  If/when you decide to do another run of kits, I would be in for +1.

Cheers!

[taemun]

+1 In for a kit.

[gdewitte]

@free_electron

I would be interested in a kit.

[Pezo]

Hey guys, just wanted to show you my version of the pulse generator (Link to the album).
I built a version with around 1m of RG174 for the delay line, the last picture shows the output signal on a 300MHz sampling oscilloscope.
Maybe I get the chance to measure it with a faster oscilloscope at the university.

Have a look at the album for a little more text.

[m100]

+1 on a kit