Beginning my foray into tube gear. Looking for some advice

[gadget73]

Its in the multiplex decoder, I recall a post on here a while ago going over one v the other and I think the conclusion was use what it calls for and it tends to work better

 

[RonSSNova]

Smoked an output tube until it melted the glass. I’ve not seen that in 50 years of tube stuff.
Hope the OPT is good.

 

[gadget73]

Thread 'Tube Substitution in Fisher 3 Tube MPX Adapters'

Mar 20, 2015

Switching gears for a bit, I thought I would shed some light on the effects of changing tube types in these chassis. But first, some light on the differences and why they exist.

The Fisher three tube MPX sub-chassis exists in a veritable plethora of various model numbers, but all are a variation of the same theme: An input tube (V100) -- a 12AT7 or 12AX7 -- buffers and provides a small amount of amplification for the composite signal in the first section, to overcome losses later on in the circuit. It also separates the 19 kHz pilot signal from the composite signal, and then further...

• dcgillespie
• Replies: 11
• Forum: Fisher

 

[GeneParmesan]

Thread 'Tube Substitution in Fisher 3 Tube MPX Adapters'

Mar 20, 2015

Switching gears for a bit, I thought I would shed some light on the effects of changing tube types in these chassis. But first, some light on the differences and why they exist.

The Fisher three tube MPX sub-chassis exists in a veritable plethora of various model numbers, but all are a variation of the same theme: An input tube (V100) -- a 12AT7 or 12AX7 -- buffers and provides a small amount of amplification for the composite signal in the first section, to overcome losses later on in the circuit. It also separates the 19 kHz pilot signal from the composite signal, and then further...

• dcgillespie
• Replies: 11
• Forum: Fisher

Wow, what a read. Thank you for posting this!