Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: whoops on February 16, 2019, 08:01:47 am

Title: Help, component identification
Post by: whoops on February 16, 2019, 08:01:47 am
Can anyone please help me identify this component ?

(https://i.imgur.com/hrtyks1.jpg)

(https://i.imgur.com/luFtKsF.jpg)

(https://i.imgur.com/3WVA715.jpg)


My MK-328 says it's a 100pf capacitor
My Peak says it's a Diode
My multimeter doenst measure anything on Diode mode (both ways)

If it's a Diode it seems the Cathote is on the + mark, and the anode is on the "-" mark, pretty weird
Title: Re: Help, component identification
Post by: Papa Jim on February 16, 2019, 08:19:20 am
Is it waxed like a vintage cap?
Title: Re: Help, component identification
Post by: whoops on February 16, 2019, 09:29:05 am
It seems to have a card/paper like inclosure, and it's waxed or was impregnated with varnish
thanks
Title: Re: Help, component identification
Post by: sluckey on February 16, 2019, 09:38:16 am
There are a gazillion interesting/oddball shaped components once you step outside of the tube guitar amp world. No telling what it really is. The polarity markings would suggest diode or cap. I'd tend to lean more toward the diode guess. Then I'd throw it in the round file.   :icon_biggrin:

BTW, it was common in the early days of diodes to mark the cathode end with a plus sign.
Title: Re: Help, component identification
Post by: whoops on February 16, 2019, 09:58:07 am
There are a gazillion interesting/oddball shaped components once you step outside of the tube guitar amp world. No telling what it really is. The polarity markings would suggest diode or cap. I'd tend to lean more toward the diode guess. Then I'd throw it in the round file.   :icon_biggrin:

BTW, it was common in the early days of diodes to mark the cathode end with a plus sign.
Thank you so much Sluckey
so if the component is a Diode, and if the Cathode end is marked with a plus sign (+), then the schematic would be like this:
Component in question marked in read

(https://i.imgur.com/OJJz9AE.png)

Does this makes sense? I don't see much sense in a capacitor being in that spot, what do you think?
Thanks
Title: Re: Help, component identification
Post by: DummyLoad on February 16, 2019, 10:40:46 am
There are a gazillion interesting/oddball shaped components once you step outside of the tube guitar amp world. No telling what it really is. The polarity markings would suggest diode or cap. I'd tend to lean more toward the diode guess. Then I'd throw it in the round file.   :icon_biggrin:

BTW, it was common in the early days of diodes to mark the cathode end with a plus sign.
Thank you so much Sluckey
so if the component is a Diode, and if the Cathode end is marked with a plus sign (+), then the schematic would be like this:
Component in question marked in read

(https://i.imgur.com/OJJz9AE.png)

Does this makes sense?I don't see mush sense in a capacitor being in that spot, what do you think?
Thanks

yes - 1/2 wave rectifier.

--pete
Title: Re: Help, component identification
Post by: whoops on February 16, 2019, 10:48:40 am
There are a gazillion interesting/oddball shaped components once you step outside of the tube guitar amp world. No telling what it really is. The polarity markings would suggest diode or cap. I'd tend to lean more toward the diode guess. Then I'd throw it in the round file.   :icon_biggrin:

BTW, it was common in the early days of diodes to mark the cathode end with a plus sign.
Thank you so much Sluckey
so if the component is a Diode, and if the Cathode end is marked with a plus sign (+), then the schematic would be like this:
Component in question marked in read

(https://i.imgur.com/OJJz9AE.png)

Does this makes sense?I don't see mush sense in a capacitor being in that spot, what do you think?
Thanks

yes - 1/2 wave rectifier.

--pete
Thanks,should I change it for a full wave rectifier?
Title: Re: Help, component identification
Post by: sluckey on February 16, 2019, 11:21:43 am
Quote
Thanks,should I change it for a full wave rectifier?
No. Just replace that diode with a common 1N4007.
Title: Re: Help, component identification
Post by: DummyLoad on February 16, 2019, 11:24:00 am
There are a gazillion interesting/oddball shaped components once you step outside of the tube guitar amp world. No telling what it really is. The polarity markings would suggest diode or cap. I'd tend to lean more toward the diode guess. Then I'd throw it in the round file.   :icon_biggrin:

BTW, it was common in the early days of diodes to mark the cathode end with a plus sign.
Thank you so much Sluckey
so if the component is a Diode, and if the Cathode end is marked with a plus sign (+), then the schematic would be like this:
Component in question marked in read

(https://i.imgur.com/OJJz9AE.png)

Does this makes sense?I don't see mush sense in a capacitor being in that spot, what do you think?
Thanks

yes - 1/2 wave rectifier.

--pete
Thanks,should I change it for a full wave rectifier?
what would be the benefit? worked as was for quite a while. replace the diode with a fast switching uF4004 or better if you want lower noise. if it were mine, i'd drop a 1n4007 (overkill) in it because that's what i have on hand... :D


--pete
Title: Re: Help, component identification
Post by: whoops on February 16, 2019, 11:41:19 am
Thank you,yes 1N4007 it goes,it's what I have in stock also