Buzzaround build....

[PorkyPrimeCut]

Hmmmmm, OK, the plot thickens.

I think I'm going to have to message the guy back & ask him for a little more info on how he came to being certain they were germanium & not silicon. All the info available online points to them being silicon. Unfortunately I can't find any info on these supposed older ones.

[digi2t]

This is what I've found so far...

http://www.surplus-electronics-sales.com/index.php?main_page=product_info&products_id=766

and it doesn't look anything like yours. Looks like a germanium diode (DO-7 clear, can see the whisker).

To me, this



looks like a germanium diode. This,



looks like a silicon diode.

Of course, looks aren't everything. But I'm just saying, guts-wise, the one you have there looks like a silicon diode to my eyes.

[PorkyPrimeCut]

I took a close-up of these N1931s, as good as I could get without a macro lens....



The N1931 code is clearly visible.

I also did a search for "50s Germanium diode". These are for sale on eBay. No markings but they look quite similar to mine. "Cat whisker" diodes, apparently...



The seller actually suggests they could be from as far back as the 20s.

Also, these Sylvania 1N39As are even closer in appearance (I think someone suggested I buy these back at the start of the thread)...



I'm starting to wonder if the seller is right and the diode just changed in construction - to the typical looking glass, red & black striped appearance -
some time around the late 50s / early 60s. This is pure speculation but worth mentioning nonetheless.

[PorkyPrimeCut]

I've just realised, digi2t, are you still referring to the diode I have on my tagboard?

[digi2t]

I've just realised, digi2t, are you still referring to the diode I have on my tagboard?

Yup. Have I gone astray?

[PorkyPrimeCut]

I've just realised, digi2t, are you still referring to the diode I have on my tagboard?

Just a little. You're forgiven though as you're still being a great help!

Towards the bottom of page 2, mcknib pointed me in the direction of a parts seller who eventually sold me these 1N193s.
From then on I think all the discussion was about whether or not they'd be suitable in my build. Looks 99% certain that they are. I think?

[PorkyPrimeCut]

I've just realised, digi2t, are you still referring to the diode I have on my tagboard?

Yup. Have I gone astray?

Just a little. You're forgiven though as you're still being a great help!

Towards the bottom of page 2, mcknib pointed me in the direction of a parts seller who eventually sold me these 1N193s.
From then on I think all the discussion was about whether or not they'd be suitable in my build. Looks 99% certain that they are. I think?

[digi2t]

DOAH!! 

OK. Sorry. The ones you pictured here,



most definitely look like germanium diodes. I would run with these.

Besides... I think they look awesome!!

[PorkyPrimeCut]

... I think they look awesome!!

Likewise!

The seller just sent me this great, old school drawing/diagram to clear things up....



....titled "General Electric 1N193 INFO Production Limited to 1950s".

[PorkyPrimeCut]

The tagboard's done....



The final 2.2m resistor arrived & is in place....



Tomorrow I'll start testing my transistors! Finally!!

[PorkyPrimeCut]

Right, I think I've done this right.

Everything but the "correct" Hfe has been calculated. The results are as follows....



So, it's looking as though the 2N404A transistors will be a better fit for the Buzzaround, right?

As to the NKT213s, should I just try'n buy a single, leaky transistor with higher Hfe for Q3 & use the first two tested in the chart?

[bluebunny]

The tagboard's done....

  I need to buy me some tagboard... 

[Cozybuilder]

Me too! I've acquired some 1950's germanium whisker diodes, have some top-hat transistors- these are just screaming for a vintage style build 

PPC- thats one fine looking tagboard build! Inspiring.

[PorkyPrimeCut]

  I need to buy me some tagboard...

Me too! I've acquired some 1950's germanium whisker diodes, have some top-hat transistors- these are just screaming for a vintage style build 

PPC- thats one fine looking tagboard build! Inspiring.

Thanks!

It's great fun to work with, especially if space isn't really an issue. While it's not always particularly cost effective, there's something really endearing about big, old school parts.

I'll be building a handful of Meathead clones on tagboard after this with the same thing in mind. I'll finally be able to use some tropical fish capacitors I have leftover from a previous build.

[digi2t]

Try them in this order (following the numbers on your chart);

Q1 - 2N404 #2
Q2 - 2N404 #1
Q3 - 2N404 #3

or

Q1 - NTK213 #2
Q2 - NTK213 #3
Q3 - 2N404 #3

Let us know how it sounds.

[mcknib]

Yep that looks the business I'm surprised it's your first tagboard effort you've obviously got the knack for it.

I've built a load of germanium FF's a coupla Rangemasters and a Silicon Mosrite Fuzzrite using tagboard

Next up is definitely a Buzzaround after seeing yours and a Selmer Buzztone someone asked me for a wee while back.

Your build has taught me a little I always stick the component legs through both holes in the tags and I like the way you've soldered some to the middle bit.

[PorkyPrimeCut]

Try them in this order (following the numbers on your chart);

Q1 - 2N404 #2
Q2 - 2N404 #1
Q3 - 2N404 #3

or

Q1 - NTK213 #2
Q2 - NTK213 #3
Q3 - 2N404 #3

Let us know how it sounds.

Will do.

Yep that looks the business I'm surprised it's your first tagboard effort you've obviously got the knack for it.....

....Your build has taught me a little I always stick the component legs through both holes in the tags and I like the way you've soldered some to the middle bit.

It's actually the second, kind of. I built a 6G15 Reverb Unit (pretty much a Fender clone) a couple of years ago. That was all on turret board but a completely different beast to a regular pedal. Using valves & being up close & personal with lethal levels of electricity was pretty terrifying.
The turret board part was an absolute joy though & I always figured I'd go that route with a pedal, one day.

If I did one thing differently with this build it would be to try'n put all the low-lying components in place on the tagboard before soldering, then do the lot in one sweep. The larger caps would have to be added afterwards but lining up all the resistors neatly (particularly the ones that share lugs) would've been a lot easier if I hadn't soldered them one at a time.

[mcknib]

Just a wee update for Digi2t

I got my DCA55 back today with the latest firmware R 3.0 and it doesn't say whether a diode is germanium or not just the usual anode, cathode, fwd voltage test current etc

It does however now tell you whether a transistor is germanium or silicon. I've not yet checked what else it does that it didn't do before

and some extra unexpected bonuses - they changed my leads for the better ones, changed the front cover I think or maybe cleaned it up! put it in a new box and gave me the old leads back and it was very quick posted it on Thursday got it back Friday so to say I'm very happy I did it is an understatement

[digi2t]

Just a wee update for Digi2t

I got my DCA55 back today with the latest firmware R 3.0 and it doesn't say whether a diode is germanium or not just the usual anode, cathode, fwd voltage test current etc

It does however now tell you whether a transistor is germanium or silicon. I've not yet checked what else it does that it didn't do before

and some extra unexpected bonuses - they changed my leads for the better ones, changed the front cover I think or maybe cleaned it up! put it in a new box and gave me the old leads back and it was very quick posted it on Thursday got it back Friday so to say I'm very happy I did it is an understatement

Jezzus Billy, get outta my head!! I was just pondering last week about sending mine for the update!

As it is now, my version will tell me whether a transistor is ge or si, but not diodes. I'm assuming that would be impossible to do, considering that there are diodes that have vF the same, or close to, ge, but that are not ge. IIRC, the v3 software also expands the ge transistor testing as well.

Well, with a glowing report like that, I think I'll mosey over to the Atlas website, and reserve my update.

[amz-fx]

But then again:

I am fairly sure that there are no Ge diodes in a DO-35 package.

More: http://www.muzique.com/news/fake-ge-diodes/

Best regards, Jack