Originally Posted by mordy
Hi Ctritical Bill,
I have seen these sub miniature tubes mentioned, and I am happy to see somebody trying them. Seems that bigger is more expensive when it comes to tubes, and these are not that expensive and usually come in lots of 4 or 8.
Could not find 6N16B-E on Ebay, but 6N16V, 6N16B-I, 6N16B-VI, 6N16B-VR, and 6N16B-Q. The VR is supposed to last 2000 hours. Would you know what these tube designations correspond to? Are there other types that would work in the LD MKIII?
From your picture it looks like you are using it as a driver tube, but some of the Ebay posts list them as 6SN7 equivalents, which would indicate a power tube.
How do you know which lead is which? How do you wire them? Same way as octals?
Could you elaborate on your flying tube set-up?
Hope you don't mind the questions.....
I am not an expert on russian tube designations but I will share what I have seen elsewhere. E means extended life, usually 5000hrs. V means military. I is for pulse oparation. Never come across Q.
I have looked at quite a few different russian sub-miniatures as well as some of the american ones. There aren't many that are suitable for one reason or another. This is what I noted down while looking for suitable russian tubes :
Subminiature triodes :
6S7B - 5 leads - single triode 250v plate
6S31B - 8 leads - single triode 50v plate
6S32B - 10 leads - single triode 200v plate
6N21B - 10 leads - twin triode 200v plate
6N16B - 8 leads - twin triode 100v plate - most suitable
6N17B - 8 leads - twin triode 200v plate
6N28B - 10 leads - twin triode 50V plate
6N33B - 6 leads - twin triode 100v plate
The plate voltage is important because it has to be within the range that the LD uses. I haven't been able to measure the actual voltage yet but taking the well known 6Zh1P as my example, that operates ideally around 120v, I looked to get close to that. Looking at datasheets is the thing to do.
Yes, I am using it as a driver tube but, with the right setup, it could be used as a power tube.
The most difficult part was identifying the pins and wiring it up, eveything is so small. The datasheet shows the pin outs but identifying the actual pin numbers wasn't clear. I found on the base of the tube, embedded in the glass, a simple line 'l' which lines up with pin 1. Just a case of following the datasheet from there :
9 pin socket tube wire
4 4 (or 8 - heater)
5 8 ( or 4)
9 no connection
I used a 9 pin socket saver and soldered the wires onto suitable sized pins pushed into the socket saver.