An irrational fear of Soviet components?

[darron]

Going of topic, in Australia when you build a house you pretty much get the options of copper piping or plastic. Copper isn't as standard these days though I don't think.

[Paul Marossy]

Metal in house pipes?? I use thermo-fusion plastic pipes made in my country or Brazil. BTW, I never buy China stuff, I don't want the houses I build to fall down and kill my clients.

In the U.S., not houses per se, but it could be in a residential building - like a high rise apartment building. It's required per building codes in certain types of construction. Where this happens most is when cheap cast iron waste piping is imported from elsewhere. Besides being inferior quality, it can also contain radioactive junk.

Copper piping is still used a lot in housing although the "Wirsbo" type piping is rapidly becoming the norm these days. Once again, they use copper water piping in certain types of construction where fire ratings make it easier to use copper than plastic. In fact, in some buildings that are classified as non-combustible, you have to use metallic piping.

[~arph]

Ever wonder where radioactive steel scrap in the USA goes?

I also heard they put it in their bullets.. shoot and forget

[mac]

Today I measured the russian transistors again, as Vanessa did.  3 of 5 were more than 100% away from the first reading. I used thick plastic bags as gloves, and sex® wax in my hands... better safe than sorry.

Copper piping is still used a lot in housing although the "Wirsbo" type piping is rapidly becoming the norm these days. Once again, they use copper water piping in certain types of construction where fire ratings make it easier to use copper than plastic. In fact, in some buildings that are classified as non-combustible, you have to use metallic piping.

Firemen do not work a lot in my country as houses are made of bricks. Most fires occur at storages facilities and factories. If Katrina Hurricane would have hit my city the level of damage would have been a lot less, that's for sure. A couple of reasons why the use of plastic became the norm. It has the advantage of being less toxic than metal, cheaper, light and durable. Even gas pipes are being replaced by thermo-fusion plastic. But in buildings, the natural oscillations make mandatory the use of copper in sewer lines and gas.

mac

[MetalGod]

Russian stuff is great. I've made some real nice Rangemaster clones with GT313s - they bias differently because they have shunt resistors in them (who else knew that?), but they can get a nice tone.

what do you mean by shunt resistors? - do they have an internal resistor between base and collector? 

I've just bought 100 of the NPNs (311) and 100 of the PNPs (313) off ebay, couldn't pass them up at £12.50 per 100.

[soulsonic]

what do you mean by shunt resistors? - do they have an internal resistor between base and collector? 

I've just bought 100 of the NPNs (311) and 100 of the PNPs (313) off ebay, couldn't pass them up at £12.50 per 100.

Yes, a resistor shunt (I don't remember where the shunt is) - my Peak Atlas Semiconductor Analyser told me and he doesn't lie - unfortunately, he doesn't tell me the value either, though I haven't had too much trouble getting them to bias up okay. If this turns you off, I'll gladly buy yours from you.

[soulsonic]

Okay, I checked my last remaining 313.... the shunt is between the Emmitter and Base. Atlas says that this makes his hFE reading innaccurate (he said it was 45). I tried to measure the possible resistance of it, but it seemed I was just getting the E-B diode resistance because it changed when I flipped the leads, so this tells me it's at least fairly high of a value. Hard to say.

Here's the full rundown of specs Atlas DCA55 told me about the 313:

PNP Germanium Transistor
Resistor Shunt between B-E
hFE not accurate due to B-E resistor
hFE =45
Test current Ir = 2.5mA
Base-Emitter Voltage = .39v
Test current Ib = 4.91mA
Leakage Current = 0.00mA (this may also be off due to the shunt)

Maybe this helps with figuring it out.

P.S. You can ignore my offer to buy them off you, I'm sure it'd be cheaper for me to just order my own from the eBay guy what with shipping and all that nonsense. Though if you wouldn't mind parting with a small handful........ I really don't need 100.

[MetalGod]

Okay, I checked my last remaining 313.... the shunt is between the Emmitter and Base. Atlas says that this makes his hFE reading innaccurate (he said it was 45). I tried to measure the possible resistance of it, but it seemed I was just getting the E-B diode resistance because it changed when I flipped the leads, so this tells me it's at least fairly high of a value. Hard to say.

Here's the full rundown of specs Atlas DCA55 told me about the 313:

PNP Germanium Transistor
Resistor Shunt between B-E
hFE not accurate due to B-E resistor
hFE =45
Test current Ir = 2.5mA
Base-Emitter Voltage = .39v
Test current Ib = 4.91mA
Leakage Current = 0.00mA (this may also be off due to the shunt)

Maybe this helps with figuring it out.

P.S. You can ignore my offer to buy them off you, I'm sure it'd be cheaper for me to just order my own from the eBay guy what with shipping and all that nonsense. Though if you wouldn't mind parting with a small handful........ I really don't need 100.

thanks for the info, I'll see how they bias up in something simple like a Rangemaster or a Fuzz Face before trying much more with them.

if you don't need 100 (who does) the ebay seller has smaller quantities up for sale.  I just bought the 100 because they were cheap enough not to matter and it's pretty much a lifetime supply for a DIY guy if they turn out to be good.

worst case scenario is they get used for the Ge junction as clipping diodes.

[soulsonic]

I've built a few boosters with the 313s and they seem to work pretty well. Sometimes they're a little noisey - but what old germaniums aren't? I like the extra pin that connects to the shell that you can earth for some shielding. If you need any more info, pinouts etc... about the 313, just let me know, I have access to the original datasheet - Pa Ruski! Unfortunately, I couldn't decipher any info about the shunt resistor, but they seem to bias up good regardless.

[RaceDriver205]

If someone wants to test some components for radioactivity, I believe you should put them on a piece of unexposed photographic film for a while. If you have it developed and it comes up cloudy, they're radioactive. (Correct me if im wrong  )

[MetalGod]

I've built a few boosters with the 313s and they seem to work pretty well. Sometimes they're a little noisey - but what old germaniums aren't? I like the extra pin that connects to the shell that you can earth for some shielding. If you need any more info, pinouts etc... about the 313, just let me know, I have access to the original datasheet - Pa Ruski! Unfortunately, I couldn't decipher any info about the shunt resistor, but they seem to bias up good regardless.

ahh, so that's what the fourth pin is for - I've have a Ge transistor like that for years and always wondered what the extra pin was for.  suppose I might as well use it for shielding if they've went to the trouble of wiring it in there - be interesting to see if it helps with noise at all.

[soulsonic]

The 4th pin - yes, the datasheet clearly lists that pin as "Korpus"..... not too hard to figure out what that means! My Russian is terrible, but I can read Cyrillic and fortunately, the majority of Russian electrical terms are almost identical to the English equivalents, so the datasheets for these oddball transistors aren't too hard to decipher.

[Chuck]

Homeland Security would have detected em.

They check for radiation.

[vanessa]

Today I measured the russian transistors again, as Vanessa did.  3 of 5 were more than 100% away from the first reading. I used thick plastic bags as gloves, and sex® wax in my hands... better safe than sorry.

To add, living in times when just about everything is scanned through airport and customs (sometimes several times before they reach its destination) for security reasons, why not ask the seller to write "Do Not X-Ray" on the side of the box? The security people will just open the box instead of it being x-rayed.

[soulsonic]

Very good point! They could maybe retain a little bit of residual radiation from the x-ray? Or perhaps be damaged? Someone please correct me if I'm wrong.

[Meanderthal]

Russian stuff is great. I've made some real nice Rangemaster clones with GT313s - they bias differently because they have shunt resistors in them (who else knew that?), but they can get a nice tone.

You're probably in more danger of radiation exposure if you live near the desert in Nevada.... or within 50 miles of Amarillo, Texas.

Well, I'll be damned! I suppose this would also apply to the GT311 npn counterpart...? Would explain the bias oddness...wasn't easy to find good sounding pairs in a standard Dallas FF circuit(no trimpots)...

[R.G.]

X-rays do not cause other objects to become radioactive. There is no residual radiation from being X-rayed, or cosmic rayed or gamma rayed.

Neutrons cause things to become radioactive.

Airport and other scanners do not use neutrons.

[soulsonic]

Thanks for clearing that up.

[mac]

X-Rays are just photons. When a sample is scanned photons makes free electrons to jump to a new energy state. The difference between states is h*f where h is Planck constant and f the x-ray freq. From a classic point of view photons do not have enough mass to break a nuclei, but this is quantum level so the chance exists, although very small.
So when the scanner is turned off, electrons come back to their proir energy level and photons are generated by the inverse process. Some of this photons hit electrons and some just leave the sample. After a while it is off.
If photons were more massive, this could be another story. For those curious souls there is a relationship between the mass of the photon and the exact inverse square law, ie the F = k*e1*e1/(r*r). The closer to r*r the more mass tends to zero.

Neutrons as I said above do not have charge but a significant mass almost like a protons, so there is no force like the Coulomb force to stop them. They can cause a severe damage to a nuclei. When broken, photons, alpha particles, more neutrons are liberated. Alpha particles have a charge so they can be stopped by the Coulomb force but the new neutrons  are free to keep breaking nuclei. Now the more particles the nuclei have the more unstable it becomes. That is because there is a force, actually two, stronger than the Coulomb force that keeps the nuclei togheter, but of much less range, of the order of a few H2 nuclei radius.

God, this is stuff I haven't talked about in more than 20 years!!

mac

[RaceDriver205]

We appear to have branched into quantum phyisics! What other topics will this DIYStompbox forum cover next?