Re: SC502 With Display Issues


Stephen
 

I understand. And you’re absolute right. I did with what I had available at the time.

Best Regards,

And thank you for your time and effort.

Sent from my iPhone 7
Stephen S. Nabet
stephen.nabet@gmail.com

On 19 Aug 2020, at 19:21, Dave Wise <david_wise@phoenix.com> wrote:



Do you think [oscillation] could be an issue in the low power supply section?
It's a much-talked-about complaint. In this particular case, it's unlikely since the transistors in question only operate in unusual cases - power off and overload, respectively.
But since we're doing Component Engineering figuring out a suitable retrofit part, why not put in 100% effort? Do work you can be proud of.

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Stephen via groups.io <stephen.nabet=gmail.com@groups.io>
Sent: Wednesday, August 19, 2020 10:00 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] SC502 With Display Issues

On Wed, Aug 19, 2020 at 05:48 AM, Dave Wise wrote:


To replace 2N3565 in the SC502 power supply, BC639 is better than 2N2222A,
100MHz vs 300MHz. Under a dollar at Mouser. But the best choice is KSC1008.
It's only 30MHz - perfect to avoid oscillation - and even cheaper. Mind the
pinout.
Ooh ok. Now I understand. You were talking about oscillation. This is the thing I didn’t grasp before from your previous post. Thank you for clearing that out. Do you think that could bean issue in the low power supply section?

On a side note, I’m trying to find parts that are readily available at my local shops because it’s just a 20min ride from my place.
And I know that if something fails, I can easily go and get them without having to order, and wait for (sometimes) a week to 10 days to get them. Yes, it’s terrible, I know.
BC639 is available. Not the KSC1008. I’ll try that.







Join TekScopes@groups.io to automatically receive all group messages.