[Boatanchors] Crystal Current

[Bill Stewart]

Tnx for the replies. 
What brought this request on was an article in the Jun 1933 'Radio' mag. 
They show a one tube osc/xmtr using a 2A5 tube. In the following month 
they have a one tube amp for the osc, using a 210. My concern is the 
xtal current. They, of course, were using the big round Bliley type xtals... 
probably a bigger slab of quartz than our modern xtals. They suggest, in 
other osc articles, the use of the fil. of a '99 tube as a fuse in line with the 
xtal...the same as using a p. lamp now days. I think the '99 draws 60ma..... 
so not too far from the p. lamp fuse. I have used a p.l. before and they 
provide a good indication of the xtal current. I wanted to know if modern 
xtals might safely work in this circuit. 
  
Tnx Mac, for the 40ma max recommendation. That might put the FT-243 
types just in the danger zone. I think, in this circuit, that the grid leak across 
the xtal (20-50K) can be adjusted for lowest xtal current along with keying 
quality. Also, the B+ may also have some bearing. After these adjustments, 
maybe ye ole FT-243 would work ok. Might be worth a try. 
  
As a side note, I am looking for a 1930s style 80m xtal...3530-3570kc or so. 
  
Tnx, 73 de Bill K4JYS