[cctalk] Re: IBM 727 tape drive

The valve audio afficionados / suppliers also offer both wisdom and components, e.g. https://skillbank.co.uk/psu/ and many other sites / blogs https://www.amazon.co.uk/Designing-Power-Supplies-Amplifiers-Second/dp/0956… https://shop.elsevier.com/books/valve-amplifiers/jones/978-0-08-096640-3 and many other titles https://www.ampmaker.com/shop/vcb-vvr-voltage-control-kit/ and numerous other kits for worked examples https://www.thatsaudio.co.uk/product-category/valve-amplifier-transformers-… Regulation is typically effected by a high voltage N-fet or similar device see e.g. - https://www.microchip.com/en-us/product/lnd150# etc etc - https://www.ti.com/lit/pdf/snva020 etc etc Martin -----Original Message----- From: Paul Koning via cctalk [mailto:cctalk@classiccmp.org] Sent: 13 October 2023 14:57 To: cctalk(a)classiccmp.org Cc: Paul Koning <paulkoning(a)comcast.net> Subject: [cctalk] Re: IBM 727 tape drive A good source for information on how to do that would be an older edition of the ARRL Amateur Radio Handbook. Those can be found, from used book dealers. I have a 1954 edition that would do well, though one from the 1960s is likely also good (perhaps better since the earlier ones would have vacuum rectifiers, which in a newly built supplly isn't optimal). Chances are those voltages don't need to be tightly regulated, not like trying to build a TWT supply... so the main thing is the transformer(s). Those too can still be found, or can be built; Hammond (Peter Dahl) is still in that business. The heater supply is typically just a suitably large 6.3 or 12.6 volt transformer. paul