No, I asked Victor for one of his oscillators and requested that he measure them, I requested the best one. Some time later he replied that this was the best one he's measured at the -160dB. So that is the one I bought. He didn't think he'd be able to make another that low again as he boards were going to be different and something about the parts, but I can't recall exactly.
What does yours measure? Did you specifically ask that you wanted the lowest -dB figure that he could make? I had to wait and he had to tweak it, with parts etc., What ever he did, to get it down to that level. I think I had to pay a little bit extra for it, it was a while ago.
I got the HP339A distortion number from you. I think you posted the pic and said it was greater than -120dB. Then looking at the image you posted it appeared to be between -123dB and -125dB.
I used the lowest (higher distortion) number that seemed reasonable.
When demian was here, he had mentioned what he does to these boards, I think adding a reg to the V+, V- imputs and changing out resistors along with other changes.
But I didn't want to fool with it then as I had the HP339A water boarding issues. Currently everything is apart and sitting in the music room I'm stuck without a bench or equipment at the moment. Kinda like Demian after the move. Except my move is within...maybe that is worse.
Cheers,
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yes, we can help..... pretty much the mods are as far as reasonable on the HP339A... so it died away. Nothing more could be done.
What help exactly do you need?
-RM
What help exactly do you need?
-RM
Oh. I would just like to buy one board or a finished unit. They aren't for sale anymore on ebay or here.
Hi Telstar,
Yes, Victor's oscillators are pretty good. I have a 1 KHz and 10 KHz from him.
-Chris
Yes, Victor's oscillators are pretty good. I have a 1 KHz and 10 KHz from him.
-Chris
How about 10hz to 200Khz with EF95s
It is from the manual of the Marconi TF1101 I restored.
Attachments
Hi Refugee1,
What is the distortion for that model? I don't think it's anywhere near what Victor has created.
-Chris
What is the distortion for that model? I don't think it's anywhere near what Victor has created.
-Chris
I'm "greening" a similar instrument, i.e with a variable capacitor, of a different make.
The best THD I got from a lamp-stabilized version with an OPA627 as the active element was about -95dB at 1kHz.
regards,
Braca
The best THD I got from a lamp-stabilized version with an OPA627 as the active element was about -95dB at 1kHz.
regards,
Braca
It is 0.5% and there is a fixed filter at 1khz that can be switched in to get 0.1%.
It is certainly up to what I want to do with a sine wave generator and restoring it was fun too.
Hi Refugee1,
The oscillator that Telstar is looking at has a lot of zeros before the numbers start. 🙂
0.1% is as far off as the moon in this discussion.
On another note, excellent work. I love hearing about electronics saved from the scrap pile!
-Chris
The oscillator that Telstar is looking at has a lot of zeros before the numbers start. 🙂
0.1% is as far off as the moon in this discussion.
On another note, excellent work. I love hearing about electronics saved from the scrap pile!
-Chris
Frex has PCBs for an LT AN67 oscillator, that does a reasonable job at 10KHz. EOSC10Kv3 - LT AN67 10kHz oscillator : new updated version !
This far my own version of the AN67 oscillator, with switchable frequency &c, doesn't work properly at all - I'm unable to get the loop gain low enough for it to stop hitting rails, so I've gotta do some tweaking - alas I keep finding other toys to play with.
This far my own version of the AN67 oscillator, with switchable frequency &c, doesn't work properly at all - I'm unable to get the loop gain low enough for it to stop hitting rails, so I've gotta do some tweaking - alas I keep finding other toys to play with.