[Drakelist] L-7 Amp Soft Start.
Has anyone on here installed a Harbach SS-400 type "Soft Start" kit in their L-7? (This is the kit with the single relay and single dropping resistor and not the one used in a Heath SB-220). I know the SS-400 was made to install in a L-4B amp. I have not really studied the room requirements, but I suspect there is little room for this board in a L-7. If it won't fit, I'll consider a time delay relay instead or redesign a board to fit any available space in the amp. (I realize some guys feel no soft start is needed for a 3-500Z tube as you feel it is "instant on", nor is needed to protect an on-off switch if a relay is used to isolate the power surge from an on-off switch. I understand all that). Just want to find out if the SS-400 will fit somewhere within a L-7 and if someone has already installed one. Thanks, Lee, w0vt ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L-7 amp soft start?
Bill, The Harbach SS-400 Soft-Start Module does not physicaly fit the cabinet as described in the documentation for L4B. However the rather crude electronic design does work with the L7 as the L4B and the L7 power design are quite similar. regards, LA9XKA Per At 04:23 16.04.2010, Bill Dzurilla wrote: Anyone know where to find a soft start for the L-7? Jeff at Harbach told me his L-4B soft start does not work on the L-7, and his universal soft start does not work on either the L-7 or the L-4B. 73, Bill NZ5N ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] L-7 amp soft start?
On Thu, 15 Apr 2010 19:23:25 -0700 (PDT), Bill Dzurilla wrote: >Anyone know where to find a soft start for the L-7? Jeff at Harbach told me >his L-4B soft start does not work on the L-7 I don't know why not, the L-7 and the L-4B are, for most practical purposes, virtually identical. Is it a physical size issue? Soft start circuits aren't rocket science, there is plenty of info on the web to roll your own. You could even use series light bulbs with a manual bypass switch. Seems to me I looked at some pics on the Heathkit shop web site one time, and you could almost trace out the circuit from the pics. In the meantime, always power up with the amp in CW mode. That reduces the turn-on surge by a bit. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! "Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime." HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://radiojim.exofire.net http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] L-7 amp soft start?
Anyone know where to find a soft start for the L-7? Jeff at Harbach told me his L-4B soft start does not work on the L-7, and his universal soft start does not work on either the L-7 or the L-4B. 73, Bill NZ5N ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
