The pdf suggests that the change was to affect the AVC. Could be.? The 6SK7 has minimum bias of about 3 volts and cut off bias of around 50 volts,? the 6SG7 range is from 1 volt to about 20 volts so swapping tubes with modifying the AVC would change the gain structure.
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-------- Original message --------
From: Jacques_VE2JFE <jacques.f@...>
Date: 10/28/22 2:37 PM (GMT-08:00)
Cc: 'Richard Knoppow' <1oldlens1@...>
Subject: Re: [HallicraftersRadios] SX-110 2nd IF Circuit Design
Hi Richard,
?
For the order of the CSR-5A RF tubes, absolutely not.
Makes no sense (intuitively) to me also, but that¡¯s how it was done.
It is a fairly rare receiver compared to the other ones made in WWII.
Maybe 1250 units made¡
There are still many in Canada (I have three¡), and the other country where you can find some is New Zealand.
?
All that you can learn about (or not) is here:
?
73, Jacques, VE2JFE in Montreal
?
I have not looked at the CSR 5 handbook but suspect you have the order of the RF reversed.?
The other tubes , like the 1853, are really not like the 6SG7.? They were designed for wide band television IF use.? As RF tubes they have rather low impedance making it difficult to get good selectivity .??
I have lost a word,? means non-beluever,? but I think the well loved SX 28? has some serious design flaws.? Hallicrafters liked to use hot tubes but they were not always used well.?
