[cctalk] Re: IBM 727 tape drive

The cost of implementing a linear regulator will be modest, measured in £s rather than 10's for the components. Much of the actual cost will be in the pin board layout; FWIW I have found 3 mm PTFE sheet, drilled as required and fitted with crimp castle posts works nicely. One merit of (wide range) linear regulation is that you can ramp up the power rail(s) during commissioning / fault finding and possibly release less / no magic essence. Regarding the audiophile magic products I think due diligence is the way forward. However, fertile ground for 1 April pranks. Martin -----Original Message----- From: Paul Koning [mailto:paulkoning@comcast.net] Sent: 13 October 2023 18:32 To: Martin Bishop <mjd.bishop(a)emeritus-solutions.com> Cc: cctalk(a)classiccmp.org Subject: Re: [cctalk] IBM 727 tape drive I wonder if makers of ham radio focused products are likely to be more economical. Tube audio has some cult aspects to it, and may have pricing to match. (Monster Cable comes to mind as an analogous case.) Yes, that works if you need regulated power. You can also use tubes to regulate (see the 1967 Handbook on archive.org). That assumes regulation is even needed, which is not often the case for tube circuits. Also, a simple shunt regulator is often adequate, either a classic neon tube or a Zener diode (or a couple in series if you need a higher voltage). I haven't worked with tube computer or logic circuits, but tube circuits in transmitters or receivers are not normally regulated, with the exception of LC oscillators. For those, a typical design would just use a neon tube shunt regulator. paul