Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would
be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate
that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views.
It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if
you would like to post something on RF Cafe's
page, please do.
Below are all of the forum threads, including all
the responses to the original posts.
Post subject: IF transformers from tube to transistor radios
Posted: Wed Jan 17, 2007 8:23 am
Joined: Fri May 19, 2006
In all tube radios that I've seen,
the IF transformers have tuned primary and secondary
windings. In transistor radios (where they used
IF cans instead of ceramic filters anyway), only
the primary is tuned. Why is this?
I can see
the obvious advantage, in that you no longer need
to "tune" the mutual coupling between the windings,
but is this the only reason behind the change? If
so, why did they insist on having a tuned secondary
in tube radios?