If that shows couple mA of current, then check voltage across Pin1 and 2 of the pot and see if you can vary it. If yu want to be safe, detach transformer. If you have a varying voltage across the pot, then you have a transformer problem. If you dont have varying voltage across the pot, then you have a fried pot.
2.9mA across each 10k resistor...voltage varys from 5.5v down to zero with pot. Dammit...something must be up with the xformers.
I have the cinemags.
I have the cinemags.
nope...all mounted correctly...they are keyed so you cant do it wrong.
One last question...one last shot...maybe reduce the 10K resistors after the pots?
One last question...one last shot...maybe reduce the 10K resistors after the pots?
Always behind. Whole day job thing😀 I'll get it up tonight. Good news is that there are no difficult parts so I will be ordering 25 kits this weekend. Will be in Georgia all week, next week, but should be able to ship on return. Only caveat is if someone wants Cinemags as well. May add time. I'll also be closing the toroid GB after I get back, so hopefully we can sum everything up nicely.
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Darn, I think I will need Cinemags....I can wait. Got a long line of F5s waiting to be built 😀 😱
ok..I can't find my camera yet. here is the update today.
I powered up the other channel which still has the buffer and all pots as well as a red and a blue led. it biases up no problem. I then swapped the xformers and same result bias with no issue.
so I am now inclined to think the mosfets might be toast for some reason.
all resistors check out all solder points are good.
with all the messing around with that board it's pretty bad off now...Mike would you have one spare channel you could send me? PM me if you do and we can settle up.
I powered up the other channel which still has the buffer and all pots as well as a red and a blue led. it biases up no problem. I then swapped the xformers and same result bias with no issue.
so I am now inclined to think the mosfets might be toast for some reason.
all resistors check out all solder points are good.
with all the messing around with that board it's pretty bad off now...Mike would you have one spare channel you could send me? PM me if you do and we can settle up.
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Buzz,
I would like to be in on the kits as well, If you need help with the Jensons' I am not far from Chatsworth.
Bill
I would like to be in on the kits as well, If you need help with the Jensons' I am not far from Chatsworth.
Bill
Allright!
So I had a spare pair of IRFP244's and put them in place and powered up the suspect channel.
Voila! apparently when something in the front end blew, likely from the suspect K170/J74s it must have blown at least one of the IRFP240's.
So, I will put a new pair of IRFP240's on order and un-buffer the other channel and see how we do.
So I had a spare pair of IRFP244's and put them in place and powered up the suspect channel.
Voila! apparently when something in the front end blew, likely from the suspect K170/J74s it must have blown at least one of the IRFP240's.
So, I will put a new pair of IRFP240's on order and un-buffer the other channel and see how we do.
In case it was not too clear from my previous posting, just wanted to reinforce that I would like to be added to the group buy list for the parts.
Irf and Jfets will be matched. They are not in the kit price, btw. I need to add a column for them. I am also going to be selling them for Aleoh J boards being released soon, so I need them as a seperate line item. Ill check about the Jensen's next week.
USPS just raised price of flat rate shipping in small flat rate box to 23.95. xtra dollar is for bubble wrap, tape, and time. I can ship it standard mail for lower price, but it increases the time substantially. Small transformers fit in box so they are a non issue.
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