I would try the MJ2995 pnp T03 transistors, these are silicon so your resistors on the bases may need lowering..
Best option is to open circuit the secondary winding to the bridge rectifier, and replace the transistors and see if it's giving out AC 150/+ volts, then connect the rectifier back and check again for DC across the output capacitor.

Thanks, I'll isolate the transformer, take resistance and induction measurements AND measure the gain factor at different freqs.
Then I'll see if I can get it running with the secondary open. (except for scope probes)

 

I decided to build the basic circuit in the LTspice simulator and observed considerable variation in operation as I adjusted component values.

Is LTspice a free app?
It does give a spike when I ground the points circuit.
If I could test out the 4399's or the NTE88's on a screen that would save some work. Can you input variations to a transformer?
Let me get the readings off of the transformer once I get it isolated.

 

Yes it's free. The common way to do transformers is to set the inductances of the windings and the figure denoting the coupling factor (coefficient) between the windings separately. The latter is usually something around .995 or more for nongapped iron laminated cores.

 

Yes it's free. The common way to do transformers is to set the inductances of the windings and the figure denoting the coupling factor (coefficient) between the windings separately. The latter is usually something around .995 or more for nongapped iron laminated cores.

Here are the isolated transformer readings.
Overall gain with center tap open and 1v sine input at 4.8kHz (maximum output) =11.5v
All the primary resistance is 1-2 ohms.
21.5mH across where R2&4 connect. The short windings are 6.5&4.2mH.
The output is 1.534H 15 ohms.
I haven't hooked it back up yet in case there's something else I need to measure.
Really likes 4.8kHz at 1v. Serious peak right there.

 

WOO HOO!!

Got it running with the NTE 88's by putting a pot at R1 and giving it intermittent power while watching the scope and BAM! off the chart! Hitting 2.2k lights it up (though it doesn't start every time) with a 600vac output. I dialed the pot down while it was running, the waveform morphed in half and the pot started smoking. (I'm admitting smoking a little pot LOL!) Need to get a fatter resistor to stick in there but I think that isolating the output is the ticket. Once I get it to run every time it's powered up, I'll hook up the bridge rectifier and see what's up from there.
Thanks for all the help everyone! I'll keep checking back with updates on my progress including scope pics and final voltage readings.
Those diodes in the rectifier are really old. One of them already broke. I have some monsters I can put in there to make it bullet proof. Might just do that first.
Never give up!

 

Nice one mate, ideally measure the pot resistance when it's working, and replace it for for a fixed resistor 1/5W rating,...

As for the diodes, use Ultrafast diodes like Uf4007...

 

Nice one mate, ideally measure the pot resistance when it's working, and replace it for for a fixed resistor 1/5W rating,...

As for the diodes, use Ultrafast diodes like Uf4007...

Thanks! I have piles of surplus stuff. I chose a MDA970a6 600v 6A bridge rectifier. Fits real nice.
I didn't have any big 2.2K resistors, so I strapped together 8- 22K 1/4W =2.8K because I had them LOL!
Other changes I've made are a 2N4170 in place of the original (rusty, unknown) SCR that I shorted.
The schematic calls for a 2N3414 for Q3 but the one in there says "GE508". It tests good.

Here is the site where I found the schematic http://www.seekic.com/circuit_diagram/Basic_Circuit/CAPACITOR_DISCHARGE_IGNITION_CIRCUIT.html

Update; I don't quite understand what's going on. I'm getting REALLY high positive spike voltage at high freq on the bases of Q1&2 and R1 is passing too much current. I'm thinking it's something to do with R1&3 balancing... No?
Still doesn't run every time it's powered up but maybe 80-90%. Need to get the 2.8K closer to 2.2. It was really touchy getting it in the sweet spot.

 

R1, 3 are different values to make sure one transistor turns on first, one is 470R the other is 1K, so ideally the lower resistor transistor will switch on first, you could put both values at 1K and see if it works, or keep them at the original values.

 

Still doesn't run every time it's powered up

Circuit simulation suggests you could try making R1 and R3 the same value, but put a cap (say 1nF) across one of those resistors to ensure circuit asymmetry and encourage start-up.

 

Circuit simulation suggests you could try making R1 and R3 the same value, but put a cap (say 1nF) across one of those resistors to ensure circuit asymmetry and encourage start-up.

Thank you. I'll give that a shot.
Would the 2N4399 perform better?

 

Would the 2N4399 perform better?

Better than what?

 

Better than what?

Than the NTE88 that I'm currently testing.

 

The NTE88 and the 2N4399 both seem over-the-top for driving the SCR gate.

 

The NTE88 and the 2N4399 both seem over-the-top for driving the SCR gate.

Those were the only TO3 PNP's that I had handy. I have a tendency to go extreme duty when I replace components, if it doesn't cost me extra. In this case they were "free" as I've had a Boeing surplus stock (plus boxes of PCB's and audio amps) for about 30 years. I've gotten in the habit of bumping up the duty to avoid future failures. It usually works out.
You don't think that a 2N4170 is "over the top"? I'm thinking it's about 10X what I need.
As long as it doesn't cause specific issues, why not?

 

The 2N4170 should be fine.