Re: SX-110 2nd IF Circuit Design
¿ªÔÆÌåÓýSteve, ?good work on all this! I think you originally said? ¡°a 6SK7 was used for the 2nd IF, while a 6SG7 is used for the 1st IF.¡±? == ??6SG7 then 6SK7 But now you show from Osterman ¡. SX-110 (1960-63) 6SG7, 6SH7? ???so I had a look at mine ? SX-110 (1960-63) 6SG7, 6SH7? >> ???while don¡¯s ?1996 Osterman? book says 6SG7, 6SK7?? ?? Also I noticed¡ SX-42 (1947-50) 6SK7, 6SG7?? ?>>??? while don¡¯s ?1996 Osterman? book says ?6SK7,? 6SC7? , 7H7 Wonder if we have the same printing or I need to get back to the eye fixer?
i did not check? all you listed; only those with a 6SG7? don va3drl From: [email protected] [mailto:[email protected]] On Behalf Of KW4H via groups.io
Sent: Friday, October 28, 2022 5:04 PM To: [email protected] Subject: Re: [HallicraftersRadios] SX-110 2nd IF Circuit Design ? Today I pulled out the big gun ¨C Osterman¡¯s book.? Looking at the IF tubes of some of the Hallicrafters (listed in order of IF) ¨C and this is not a comprehensive list ¨C I ¡°think¡± it¡¯s possible to derive at least part of what may have been going on.? Note that there are a lot of 6SK7¡¯s and 6SG7¡¯s from the late ¡®30s through about the mid-¡®50s.? The 6BA6¡¯s began to appear sometime mid-¡®50s, and by the early to mid ¡®60s the 6SG7¡¯s and relatives were mostly gone.? According to Radiomuseum, the first year for the 6SK7 was 1938, and the first year for the 6SG7 was 1941.? ? Now, look at the SX-110, and how it followed the SX-99.? Timing is important.? The SX-99 was in production from ¡¯55 to ¡¯58, and then the 6BA6¡¯s came into favor (smaller base and other advantages).? Hallicrafters produced the SX-100 and SX-101, saw the advantages of the 6BA6 design, and may have literally tried to clear their stock of the old 6SG7¡¯s and 6SK7¡¯s with the retread of the SX-99 in a more ¡°jet age¡± style cabinet. ? The reason for using both tubes may not have been technical, it may have been a business decision.? They may have had a large stock of 6SG7 and 6SK7 tubes and wanted to move as many out as possible before they became a liability. ? As a disclaimer ¨C this is nothing but a wild guess based on the info below.? ? 73 ¨C Steve, KW4H ? SX-23 (1939-40) 6SK7, 6SK7 SX-24 (1939-43) 6SK7, 6SK7 SX-25 (1940-46) 6SK7, 6SK7 SX-28A (1944-45) 6L7, 6SK7 SX-42 (1947-50) 6SK7, 6SG7 SX-43 (1947-50) 6SG7, 6SH7, 6SH7 SX-62 (1949-53) 6SK7, 6SG7 SX-71 (1949-54) 6SK7, 6SK7, 6SH7 SX-96 (1954-56) 6BA6, 6BA6 S-85 (1954-57) 6SK7, 6SK7 SX-99 (1955-58) 6SG7, 6SK7 SX-100 (1955-62) 6BA6, 6BA6 SX-101 (1955-58) 6BA6, 6BA6 SX-110 (1960-63) 6SG7, 6SH7 SX-111 (1960-63) 6CB6, 6DC6 SX-115 (1961-64) 6DC6, 6DC6, 6DC6 SX-117 (1961-65) 6BA6, 6DC6, 6BA6 SX-122 (1964-71) 6DC6, 6BA6, ?=======trimd ? ?
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don Root