New build started; new old Fluke! What are you up to?

[Phil_S]

I really wanted a hand held Fluke, but I wanted it cheap. eBait sometimes provide a reward to those who are patient. Here's the 8025B, needed a battery and leads (both of which I have). This appears to be an older mil-spec item, over 7" long and 2" thick; I think maybe this was spec'd for the battlefield. Sturdy doesn't begin to describe it's appearance. There is a minor scratch on the window that you can hardly see and that seems to be the only thing wrong. The monster Fluke fuses are present, whether or not blown, I don't know. The clarity of the display and response time to give a reading are really outstanding. Maybe this is no big deal for those of you who have been using a Fluke for years, but I really wanted to tell someone who would appreciate it. Cost with shipping was $27!

I've acquired a pretty good size bone pile over the last few years. This is an organ chassis that came with a pair of Tung Sol 6V6, pair of Mullard EL84, a 5U4GB (USA, forget what brand) and one 12AX7. There were two SE OT's for the EL84's, and those have been removed. The PT and OT are original. The choke is of unknown value, from some other chassis acquired a couple of years ago. I did some testing and think it is maybe 3H-5H, and, in any case, giving how beefy it is, I think it should work just fine between B+1 and B+2 for the screens. This chassis is only about 1" high, so I made a panel for the pots from the scrap of another chassis I cut up.

I thought maybe I could fit a California Dreamer (AX84) in this, but it quickly became apparent that a long chassis with a turret board would be needed. I downshifted to a Tremolux, which I got started on yesterday and did a little more today. After labored thinking for many hours, I decided it would be best to just dive in and see if I could make it happen as a PTP build. I'm only doing the "instrument" input, so I decided to parallel both sections of V1. I've got the B+ rail pretty well finished, the gain tube, and the PI. There's a lot yet to go. It feels good to get started. As I typically do, some parts are new and others are recycled. Please don't get all worked up about the CT wires going through the hole; that's just to keep them out of my way. There's a ground post in the middle near the PT that has nothing on it just yet.

I realize that I'm probably breaking a number of anti-hum rules here. My general experience is that PTP amps can be very forgiving. There are three filter caps, so each is a ground node that will have a ground wire to the ground post. I think you can see the ground lug for cap #3 is pretty full and I'm a bit concerned about whether I can actually solder all that stuff. If it looks like it won't work, I'll string a bit of copper between two lugs and use it like a very short buss.

I still have not figured out where I'll lay out the bias supply and exactly how the tremolo tube will be dressed. It is an adventure that unfolds as I go along and I'm just having faith it will all fit. The main source of the challenge is that I didn't get to choose the tube socket locations. Yes, I could have moved everything, but, really, what's the fun in that?

Well, thanks for letting me drop by for a visit.

Phil

[brentm]

I have an old 77 that looks similar. I still prefer it to my 87-5 at times. Pops up ohm readings faster.