I still have those (made in France) AMPEREX/PHILIPS YD 1130 used in the
original SB 220- the ones with graphite anodes, remember? When looking into
one old PHILIPS tube manual on the YD 1130, the tube data is exactly the
same as the EIMAC 3-400Z but the outline is as the 3-500Z. So, the question
is maybe the modern 3-500ZGs are = the YD 1130? Also: will they be usable
after so many years? I plan to warm them up or at least 24 hours before
using them. They are unused in original cartoons. Did EIMAC in 1970 sell
them under their own name? Because the tubes I had in 1970 had the EIMAC
name on them but looked like the YD 1130.
Prosit de Hans SM5KI
----------
>Från: measures <measures@vcnet.com>
>Till: <nospam4me@juno.com>, "AMPS" <amps@contesting.com>
>Ämne: Re: [AMPS] sb 220 update that was bounced the first time sent in...
>Datum: tor 11 nov 1999 08.58
>
>
>>
>>
>>>I removed the chassis from the case to first find the ALC
>>>electrolytic capacitor strewn about the bottom in confetti and
>>>foil.
>>
>>:There is no such capacitor in the ALC circuitry -- in the 110VDC
>>supply,
>>:yes.
>>
>>Correct, wrong label and most of the 110 volt supplies measure close to
>>120 vdc resting.
>>
>>>Parasitics and or a tube problem might be the next thing to
>>>investigate.
>>
>>: Parasitics that are intermittent are not easy to investigate.
>>
>True enough, however, there are clues.
>
>>It's interesting that the excessive voltage happens after both tubes have
>>been sitting on for a few minutes. As soon as I get more time to set
>>things up, I'll have the spectrum analyzer log what it sees.
>>
>>>The unit fired up without tubes showed no problems at the
>>>alc point, then each tube was tried in individually at both
>>>locations. Again, no abnormalities observed.
>>
>>:Be sure to remove the wire between the bias contacts on the relay and
>>the
>>:110VDC power supply. If you don't do this, a shorted tube can easily
>>:destroy the filament transformer.
>>
>>In your opinion, would a series glitch resistor in the bias supply
>>prevent xmfr damage?
>
>yes. 10k ohm, 2w to the bias contacts ought to limit the short circuit
>current to a safe value.
>
>>Since the meters are near hens teeth to replace,
>
>Harbach has them.
>
>>I'd like to protect the movements if possible.
>
>A meter/shunt protection circuit is at Figure 2 on my Web site.
>
>>I hope to work up a
>>circuit to do that properly. Notes in the original owners manual about
>>the meter movement values to follow once I confirm them.
>>
>The movements are 200uA and approx 1k ohms.
>
>
>- Rich..., 805.386.3734, www.vcnet.com/measures.
>
>
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>
>
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