| Worth my while? [message #9342] |
Sat, 19 November 2005 19:20  |
Jeff
Messages: 16
Registered: May 2009
|
Chancellor |
|
|
|
A question for those with some building experience... This guy says that all other parts can be found "off the shelf"...
Is this correct, and if so, is this worth going after??
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5830612000&rd=1&sspagename=STRK%3AMESE%3AIT&rd=1 Thanks,
Jeff
|
|
|
|
| Re: Worth my while? [message #9343 is a reply to message #9342] |
Sun, 20 November 2005 04:10  |
Damir
Messages: 1005
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
Good price, but 42VA and 55mA DC (with cap input) are not much, and 385-390V DC specification is a little strange to me (no AC secondary voltage given) - that probably means that you can expect this voltage/current after rectification? We need to know AC secondary voltage (probably about 300V AC if 390V DC is specified). You`d need 250-300V DC "through" the tube, and 45-65V "through" cathode resistor tipically for 2A3, and about 10-15V voltage drop through the OPT primary winding resistance. It can work like SS diodes "bridge" rectifier, with small, "tuning" input cap to get voltage you need, then LC filter. With full specs (secondary AC voltage, primary and secondary resistances), you can model the PS with "Duncan PSU II" program.
For the other, "off the shelf parts" you`d need two output transformers, say Hammond 125ESE (~$36 each), two chokes, tubes and other mechanical and electrical parts.
If you choose to build this project and have some additional questions, try "Group Build" forum.
|
|
|
|
| Re: Worth my while? [message #9344 is a reply to message #9342] |
Sun, 20 November 2005 06:18 |
PakProtector
Messages: 935
Registered: May 2009
|
Illuminati (2nd Degree) |
|
|
|
I'd say, "probably not". Electronic Tonalities aka Bottlehead, sold off his spare Iron just a bit ago. Doc has never to my knowlege used any more Iron than he has to. How else do you think his prices are so low? He has taken special care to get away with *JUST* enough Iron. For a ground up experimenter, it is best to run more Iron. It leaves you room to experiment without blowing anything up, or making it hum. Or better still designing with L-C filters... IMO, wimpy PS makes a wimpy amp. The amp is afterall just modulating the PS.
cheers,
Douglas
|
|
|
|
Posting Rules
Members
Search
Help
Register
Login
Get a T-Shirt!
