From: Stewart D Lyon [slyon@SPACEVECTOR.COM] Sent: Sunday, October 26, 1997 12:19 AM To: HEATH@LISTSERV.TEMPE.GOV Subject:Soup Up the SB301 for $7 Soup up your SB301 for $7.00 or less. If you are thinking of replacing the tubes in your -301, the following may interest you. The tubes suggested will provide a theoretical open-loop gain increase of 3 to 3.5. I don't have the necessary test equipment to verify this but practically the receiver will be noticeably more sensitive. Position Remarks Type Class gm Price** V1(RFamp) Orig. 6BZ6 SemiRemote 8K --- Replacement 6GM6 SemiRemote 13K $3.00 V6(1stIF) Orig 6BA6 Remote 4.3K --- Replacement 6AH6 Sharp 9K $2.50 or 6HR6 SemiRemote 8.5K $4.00 Notes: Retune rf coils and T3 after replacement. 6AH6 provides smoother AGC action but tends to overload when used as a monitor of local CW xmtr. Do not change V7 type - circuit may oscillate! BTW - The 6HR6 is a suitable replacement for the SB101 RFamp(V10) for the 6AU6 or 6HS6. **Prices are from Vacuum Tubes Unlimited at http://www.cinternet.net/~vactubes/index.html 73, Stu W6CUX (updated 7/17/00)