Re: S-38B, variations
开云体育Jim, thanks for finding this In reading above this quote ?it says the quote was from the 1937 ?for Australia. I have been wondering when UL made and enforced similar statements. I looked and found almost nothing but around 1950 magazines advertised UL approved lightning arresters. Was UL giving quiet approval to radios all along?? … And that is just a question. Too bad we can’t find old UL standards ..even for household appliances ? From: [email protected] [mailto:[email protected]] On Behalf Of Jim Whartenby via groups.io
Sent: Tuesday, November 5, 2024 5:01 PM To: [email protected] Subject: Re: [HallicraftersRadios] S-38B, variations ? See: Radiotron Designers Handbook, 4th Edition, page 1268, (C) Earth Connection ? " Power units and sets of the transformerless type shall have the live parts of the inner structure isolated from the case or frame by an isolating condenser or other approved means, which shall not be capable of passing a current exceeding 5 milliamperes to case or frame when the full rated voltage is applied in the normal manner of operation." Jim ? Logic: Method used to arrive at the wrong conclusion, with confidence.? Murphy ? ? On Tuesday, November 5, 2024 at 02:06:02 PM CST, don Root <drootofallevil@...> wrote: ? ? Richard, I was quoting you? From Oct 28 RE “Is there an equivalent in the B?”? ?I would say NO. In version C ?they lifted B-minus off the chassis, but not really completely; one of the things that didn’t move is quite obvious on the drawings. I believe the resistor is part of the necessary change when ??version C moved B-minus off of the chassis. ?Without that 470k resistor in the C version [D,E too] one of the grids will float. I am trying to redraw part of the schematic to verify my thinking, in the mean time I don’t want to corrupt your thinking while you unravel the redesign. Too many people don’t see the changes, that halligan has hidden. ? ? ? -- don??? va3drl |
don Root