Re: SX-110 2nd IF Circuit Design
¿ªÔÆÌåÓýSteve; and dedicated followers; I see no indication of variations or changes to the 42 in MY second edition Ostermans or in MY Dachis 1996 printing. They managed to find the later revision info to list for the receiver tube functions. I did see that FM ?went from 27 to 110 MHz [but ?I¡¯ll bet the dial is in ¡°Mcees¡±] allowing the SX-42 to do old and new FM bands Seems to me I read somewhere about the 6th band but? my take was that by production time, there were 6 bands so that was fixed. ? I just ran into the June 47 service bulletin on BAMA and on the ?first page under TUBE TYPES AND FUNCTIONS, it says for the first 7h7 ?¡°1st f-m limiter amplifier¡± ?, the other is? ¡°2nd f-m limiter-amplifier¡± ???but the schematic strips the ¡°f-m¡± and the ¡°amplifier¡± leaving only ¡°limiter¡± Old or not there should be a hint here. Richard¡¯s comment just arrived now, as to first produced year, I see both Dachis and Osterman showing 1947, and the first manual I have seen says January 1947 at the top. What I have seen on BAMA information has no 1946 dates, so I looked in QST and near the top found Halli adds: Sept 46 and before see s-38 and s-40 no sx -42 then Oct 46 ..Sx 42 first add ?I found in qst ?coming soon? look at the first simple sketches ??? nov 46? says first reviews ??? dec 46? first indication that it is/WILL BE ?is for sale? ..seems to be available ??? so other than the early test units it must have been 1947 before any consumer units ?went out the door, but it is close. We can wonder if any of those 1946 early units are around ? Seems we are off-topic again a bit Don VA3DRL ? From: [email protected] [mailto:[email protected]] On Behalf Of KW4H via groups.io
Sent: Monday, October 31, 2022 5:18 PM To: [email protected] Subject: Re: [HallicraftersRadios] SX-110 2nd IF Circuit Design ? On the SX-42:? Osterman¡¯s book indicates that there were several circuit changes during the production years of this model.? One of the back stories appears to be what happened with FM radio.? From 1936-46, FM was in the 42 ¨C 50 Mhz band.? However, the FCC required FM stations to move to the new frequencies of 88 ¨C 108 MHz by 1948.? In response, Hallicrafters added a sixth band, to bring the coverage up to 110 MHz.? What¡¯s really confusing is that the model number stayed exactly the same despite all the circuit changes. ? 73 ¨C Steve, KW4H _._,_._,_=trmd |
don Root