Different F5 panels (with and w/o Phase Lock)

[wassermann]

I'd like to show an interesting difference between two photos of F5 operator panel. I downloaded these pictures from two different sites of Fisher dealers. Both photos show definitely the F5 panel - there is the "f5" name on it. But the panels are not the same. One of them lacks "Phase lock" button, and "Freq" is located on the opposite side.

How to explain this? I presume that the panel without "Phase Lock" shows some prototype example, which never hit the market, as it was quickly replaced with the well known variant.

Cheers,
Michal

 

[Terry in PA]

Yes the one with out the phase lock button is the very first model made . Prototype detector !

 

[Elton]

n/t

 

[Cal_Cobra]

This is just a guess, but notice the button on the F5 on the right is Freq (pre-production model), and the other is Phase Lock, so the Phas Lock button was lacking on the proto. The Ground balance knob is also a button (you can click in inwards, but on the production model it does nothing). Perhaps on the proto model the Phase Lock was accessed with the ground balance knob switch (which would make sense).

Can't understand why else they used the type of switch/knob they did on the ground balance on the production models.

 

[woodwizard]

that nonfunctioning part of gb knob has had me wondering since I got my F5-now ya know.

 

[Bill Ladd]

remember the big delay in the F5's release? That was why.......