|
Title: Valiant VFO mod. & Zener? Post by: stevef on October 30, 2005, 10:30:28 AM I am doing the VFO modification (K6HLO, WB0TOW, etc.) to my Valiant. Where in the world can I find a 150v, 5w Zener ?
Tnx, Steve KK7UV Title: Re: Valiant VFO mod. & Zener? Post by: n2bc on October 30, 2005, 12:40:57 PM Just series a bunch of lower voltage jobs. I used a string of 1N5357's 20V @ 5W - Seven in series will give you 140V @ 35W, the much higher than needed wattage will keep them stable.
Have fun! 73, Bill N2BC Title: Re: Valiant VFO mod. & Zener? Post by: K6JEK on October 30, 2005, 01:36:45 PM NTE part NTE5161A
Mouser part 526-NTE5161A NTE parts are common as dirt so I imagine Newark and Allied have them too. I've also purchased high voltage Zeners from Surplus Sales of Nebraska. Jon Title: Re: Valiant VFO mod. & Zener? Post by: Steve W8TOW on November 01, 2005, 09:19:17 AM I typically use NTE subs....
gl...remember, if you use the Hammond P-T 124E as a dirver trany, and either PP or Parallel 12AU7, you must "back" connect it... vri 73 steve 8tow Title: Re: Valiant VFO mod. & Zener? Post by: stevef on November 06, 2005, 06:27:39 AM Thanks all, I found a Zener.
Steve, What is wrong with the stock transformer? - or rather, why the need to use the Hammond? TNX, Steve KK7UV Title: Re: Valiant VFO mod. & Zener? Post by: W3NP on November 06, 2005, 02:10:35 PM I typically use NTE subs.... gl...remember, if you use the Hammond P-T 124E as a dirver trany, and either PP or Parallel 12AU7, you must "back" connect it... vri 73 steve 8tow Steve - what exactly do you mean by "back connect" it? Reverse the primary and secondary connections? I have seen mention somewhere of this and using a resistive divider on the "New" secondary to apply grid bias. What is the reason for "back" connecting? |