Sometime during the production of the TR7 the 470K in series with pin 4 was added to provide the high level input. The three rigs I have all have it. It was also added by the service department to rigs sent in for repair. There was a note added to the owners manual regarding this at some point.
On Tue, 4 Feb 2025 15:09:02 +0000 (UTC)
"Evan via groups.io" <k9sqg@...> wrote:
Yes for the TR-7A and possibly late production TR-7. ?One pin is for "high output high impedance" while the other is "low output low impedance"; ?basically just a resistor between the two pins. ?
On Tuesday, February 4, 2025 at 09:39:44 AM EST, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
Indeed.?
I thought I¡¯d heard that there are two audio inputs to the TR7. I¡¯m going to have to look at the service manual, as the owner¡¯s manual only shows pin 4 as n/c. Perhaps this low level element could directly feed the low-level input, if it exists¡
Steve Wedge, W1ES
--
73
-Jim
NU0C
Jim Shorney
