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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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21st Jan 2010, 12:26 am | #1 |
Hexode
Join Date: Jul 2008
Location: Toulouse, France
Posts: 406
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IF frequencies on Telefunken Bajazzo circa 1955 and 1956
Hi !
I own a couple of B7G based valves portable from Telefunken. They both have VHF FM (87.5 to 100 MHz). The valves complement is as follow DC90, DF96, DK96 (55)- DK92 (56), DF96, DF96, DAF96, DL94 (55) and DL94+DL94 (56). So they look really identical, but, The 1955 set has an IF frequency of 10.7 MHz from the VHF head up to detection. The 1956 set has an IF frequency of 10.7 MHz for the VHF head, but it is converted to 8.35 MHz strait out of the VHF head, and it stays at 8.35 MHz up to the detection. Both are really good sets on FM, able to separate strong over modulated signals (as are the "junk" radios these days), sensitive, sound is very good, etc... So I wonder what could have been the rationale for the modification of the IF strip ? Benefits ? or else ? What do you think ? Thanks a lo for your help and advice ! |