Alright, alright. I'll setup the Clegg tonight after dinner. Google maps says we're 128 miles apart so, I dunno... maybe.

Seems very nice to me, simple and straight forward, nice solution Mike. The only thing that may improve reliability in case of transients etc is adding a resistor of e.g. 1K in the source of the lower FET. That prevents big current spikes that can blow the zener and upper FET

The heartbreak of six?



1 contact on 6m AM in the last 3years.

klc

Mike,

When the bottom 'fet turns ON, its Drain goes close to ground, with the 390K resistor as a load. Then, the Switched B+ Out, from the Source of the top 'fet, has a 10V zener going from B+ to ground. That doesn't look right. What am I missing here?


Don

Perry,

Last time I checked, the stock DX-100 modulator screen voltage came from the center-tap of the HV bleeder resistor. That puts about 375 volts on those screens no matter what your LV supply is.  If you want to take screen voltage from the LV supply, you'll need to switch it with a relay or something. Was that part of the mods you made?


Don


P.S. Nice video. That's the best I've ever heard George.

Don't make me drag out the old Clegg 99'er, Kevin. It would only make you sadder.


Don

Well thats sure a lot to take in lol. Before solid stating, LV was 380-390vdc. Book says it should be around 360. So with my higher line voltage, its right in line. After solid stating, it bumped the LV up to 430-440vdc. I noticed that when moving from cap input to choke input, it brought the voltage down much lower than before solid stating, around 280vdc. So I dont know if bringing the voltage back to where it was originally, was behind the switch. Tim says "This should provide lower screen voltage to modulators and lower voltage to VFO tube. Ideal screen voltage for the 1625 modulators is between 200 and 250 V. Around 250 volts for screens will work very well." So i reckon thats the reasoning for the switch. Anyway, this rig has been running so darn good since I replaces the LV supply, i think im just going to leave it. With exception of a 3 diode limiter just for safety, not for hard limiting. After doing a lot of timmy's mods, im seeing 140% positive before even hitting 100% on the negative, low distortion, the thing runs cool (with a temp probe floating in the center of the case, it doesnt go above 110 F even after a 4 minute transmission), and guys are having a hard time hearing the difference in this and in my Anan 200D and im just using a D10-4 plugged into the front with no processing, as opposed to an ANAN with EQ, multi-band compression, and an SM7B. But im the type to not sit on my hands and "Fix it till its broke". I dunno, you guys tell me... Its not great, but not bad for a 60 year old transmitter and a 40 year old microphone...

https://youtu.be/RXYBqnBRUvQ


Thanks for all the insight gentleman...

https://alexander.n.se/valkommen-till-alexandersondagen-2-juli-2017-2-2/?lang=en

Link to info on the next SAQ transmissions on June 30th, 2019.  Don’t worry about the 2017 date in the above link.  It will take you to the June 30 2019 info.

Bleach?  Insane!

I clean dials with either Novus Polish system, #1 and #2 or with Flitz polish, using Q-tips.  I avoid touching the lettering itself.  Too easy for it to disappear in a flash. 

It's (almost) summertime and 6m is easy.

Lot's 'o SSB and FT8 but no AM on 50.400 Mc.

Sad.

klc