I haven't yet seen even a BL with 16mA Idss, let alone a GR. Yes, the pins are DGS, looking from the bottom, face up. Battery positive on D, battery negative on GS together.
Do you not have a cheapo DMM to use the ampmeter directly? It's always good to have a few cheapos around, not for accuracy, but to be there. I got a few from fleabay including one for $9.99 that give me hfe, capacitance, etc. Sometimes all you need to know is that you're in the right ball park.
Then it goes to the factory culling and batch stamping. You got em from a trusted source? I personally never found a 16mA GR. Up to 6mA I have seen the odd one.
P.S. Mine were always Toshiba only.
I got them from Futerlec.com I dug out my cheapo DMM which gives me different ranges - still pretty much the same - the DUT that measured 1.55V (15.5mA) gives me 17.42mA on the DMM - the low DUT that gave me 0.28V gives me 3.16mA on DMM. This seems to confirm the measurements, now how do I check these parts are kosher? I don't want to build a Vreg around them for them to fail !!
Edit: Aha, Thanh1973 a cross post - you hit the nail on the head - and were they good working parts - just mis-labeled? If so then hey ho these only cost me $0.18 each & a mix of grades is good! I'll sort them into ranges next & see what I have so others might benefit from a purchase through them if you don't mind spending the time measuring (5mins)
Edit: Breakdown as follows:
12 GR grade
18 BL Grade
10 V Grade
Edit: Aha, Thanh1973 a cross post - you hit the nail on the head - and were they good working parts - just mis-labeled? If so then hey ho these only cost me $0.18 each & a mix of grades is good! I'll sort them into ranges next & see what I have so others might benefit from a purchase through them if you don't mind spending the time measuring (5mins)
Edit: Breakdown as follows:
12 GR grade
18 BL Grade
10 V Grade
Last edited:
Hmm, is there any way I can test them? - it's a hassle getting a refund & the cost of postage will eat it up. Selling them on ebay! - where's your ethics, man
If they do the same thd, gain, and noise in a given circuit VS trusted ones that fall in to stamped range, they can be OK, just a cheap offer they got for an accidentally mixed batch then, maybe. Since you idss labeled them, if you get some matches they can be usuable. Say if I had them, I would substitute a similar idss one in my phono's second stage which has no loop feedback, and I would compare FFTs and gain. If with different gm and noise, the floor would go up, thd too, and gain would missmatch a lot.
... Selling them on ebay! - where's your ethics, man
Hi John, my ethics are under a large pile of 'would be' Alps, Cerafine and NotOldStock tubes
See if Spencer has some Toshiba left, most of us have sourced 'm from him.
Watch the quality of zener. Many bad ones pop up lately. Especially those with plastic case that look like diodes. I use big cap across them, and I get into the trouble of using a resistor in its place if I can see noise on the oscope on the reg's output. Which is a pitta since I have to tune it with the under Vgs resulting idss of the jfet tail Vref ccs. And 9 out of ten, no its not a standard value.
Hi John, my ethics are under a large pile of 'would be' Alps, Cerafine and NotOldStock tubes
See if Spencer has some Toshiba left, most of us have sourced 'm from him.
Am I right in thinking that LEDs + diode can be substituted for the zeners? This seems to be more flexible, less noise & less hassle, if true!
No, hopping on my chair. But we don't have the proper smiley.
Anyway, you are right, that is why I enjoyed the sarcasm. Too much trash online. We have all got our share.
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