EEVblog #306 - Jim Williams Pulse Generator

[Christe4nM]

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.

Good idea, count me in

[spelunker]

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.

Good idea, count me in

Hi,

YES, you may count me in also.

George

[EV]

Hi  free_electron

Are you going to do more these kits and sell them on eBay?
I am interested to buy one.

[free_electron]

Right, lets do another run. I will modify the board slightly in two aspects : a slit in the back that allows you to easily solder a stub of 'hardline' ( rigid coax) so people can experiment withe stretching the pulse.

A different power switch. The current one is a bit iffy to stick through the side of the box. I will stick it through the top. Instead. I'll see if i can lasercut the holes for switch and led in the boxes.

If you want kits: post your name and how many. I will leave this open until the 20th of january. After that i collect the count and order boards and parts (iteadstudio and digikey/mouser). Shipping inside us is around 6$ outside about 15. I use the standard flat-rate  small usps box.

[fmaimon]

I'm in for 2 kits!

[EV]

@free_electron

I sent an email to you.

2 pcs

[Neganur]

2

[tymm]

I would be in for 2 -- thanks!

[Christe4nM]

Yep I'm in: 1 is fine for me

[BravoV]

FE, any chance to use BFG541 instead of 2N2369 ?

Its much cheaper (checked thru findchips) and with the same price as single 2N2369, you can supply more than one for the BFG541s in the kit for us to play/select among them and spares as well just in case it went kaput, also its hell a lot faster too (150 ps) and less voltage.  Info HERE

If you're going with BFG541 , count me in for 1.

PS : Although there might be some extra work for adapting with the new footprint at the pcb.

[TorqueRanger]

Right, lets do another run. I will modify the board slightly in two aspects : a slit in the back that allows you to easily solder a stub of 'hardline' ( rigid coax) so people can experiment withe stretching the pulse.

A different power switch. The current one is a bit iffy to stick through the side of the box. I will stick it through the top. Instead. I'll see if i can lasercut the holes for switch and led in the boxes.

If you want kits: post your name and how many. I will leave this open until the 20th of january. After that i collect the count and order boards and parts (iteadstudio and digikey/mouser). Shipping inside us is around 6$ outside about 15. I use the standard flat-rate  small usps box.

What is this going to cost beside the shipping???

[EV]

I don't know, but the old price seems to have been $ 28 on eBay.

[olepr01@gmail.com]

1 kit pls 

[free_electron]

people who are on the list so far :


Christe4nM 1x
Spelunker 1x
EV 2x
fmaimon 2x
Neganur 2x
Tymm 2x
BravoV 1x with BFG
 olepr01@gmail.com 1x
Wsalden 1x

[nadona]

I like to have one, too.

[Barryg41]

I will take one also.

[olegjay]

Please put me in for one.

[Echo88]

Id like to have one too, please. 

[casinada]

+1

[free_electron]

I am running this project on another forum where i am active as well. The goal is to bring the price down and benefit both forums. Now, here is a bit more information :

Due to the volume i will do a bulk order of PCB's . This means  you will be able to order just the PCB. Cost is probably going to be around 2 to 3 US$ for the bare pcb + shipping. Since that can be in an envelope shipping anywhere in the world could be like 1.5$ ...
People wanting just the bare board : let me know how many you want : i will add to the PCB column. Two or 3 pcb's in an envelope should work. More would push shipping up a few dollar.
If you wan tsome extra blank pcb they can be added to the kit for just the cost of the board. the shipping box for the kit is large enough and it has no impact on the price.

CAL option . This is a CALIBRATED version. I charge 5$ for this privilege . What i do is build the Pulse section. I install the 10 meg , 10k 2pf , 50 ohm , transistor and sma connector. Verify the system does generate correct pulses and i make a screenshot from the pulse of YOUR unit. You get the screenshot in electronic format by email. The measurement will be done using a very fast scope. I will post the scope model number tomorrow. i need to look it up. It's got 20Ghz analog bandwidth ( i believe) . So you need to solder the entire switcher section.
*** THE 5$ CAL FEE FROM ORDERS ON THIS FORUM WILL BE DONATED TO THE SAGAN FUND ***

Due to the combined action i can shave off a few dollars. I will post a final price end of next week ( when the order time closes ) . Due to chinese new year coming i need to order then.
Any excess money due to penny pinching will be donated to the 'Sagan fund' as well.

( note only the 5$ from EEvblog users goes to the Sagan fund. The Cal fee from the other forum goes to the other forum to pay their bandwidth ( they are a free forum also) . Trying to keep things fair. )

people who are on the list so far :

Code: [Select]

                  Kit   : CAL  :  PCB
Christe4nM         1x   :      :
Spelunker          1x   :      :
EV                 2x   :      :
fmaimon            2x   :      :
Neganur            2x   :      :
Tymm               2x   :      :
BravoV             1x   :      :           with BFG
olepr01@gmail.com  1x   :      :
Wsalden            1x   :      :
nadona             1x   :      :
Barryg41           1x   :      :
olegjay            1x   :      :
echo88             1x   :      :
casinada           1x   :      :

so let me know what features you want so i can finetune the table above.

[BravoV]

Geez.. why I'm the one who only want BFG ?  Also is there any plan to adapt the pcb for the BFG's footprint ?

Vincent, on every kit, does it came with "more than" one transistors ? I'm worry only one is not enough, whats you plan on how many you're going to purchase on this BFG ?

Btw, I can't lurk here all the time waiting for your announcement at ebay, cause prolly I might missed the bidding. Don't have any problem at all paying you in directly in advance on CAL'ed version, please PM me your paypal addie.

[EV]

I take also the kits as calibrated. I can also pay directly in advance to you, if you mail your paypal address to me.

[andyturk]

Put me down for one calibrated kit please.

[free_electron]

I will accept paypal directly. No problemo.
The pcb will not be adapted to the bfg footprint. Simply solder the tab of the bfg in the hole of the 2n, use one of the emitters to inject into the sma and use a short piece of bare copper to tack down the base.

The transistor needs to be floating to guarantee as fast a pulse as possible. I looked at the pinout of the bfg so you can solder it like that without problems.

For the bfg i was going to get you as a courtesy. Two or three. I will not test those as it is not the jw design. Anyone is free to play with any transistor he wants. The board is made for the 2n2369. The kit will have two of those and i will test both to see if they avalanche around 40 to 60 volts.
 I cannot start buiding custom kits for everyone. Is you want to play with crazy things : get a few bare boards.

[BravoV]

Thank you Sir !  Check your PM please.