[Amps] Real danger to use the ORANGE button

[Kevin Stover]

I did this with my TS-520 back in the mid 90's when I started running PSK31 and RTTY. A 9V battery connected to the outside connections on a 10K linear taper pot built in an Altoids tin.

Tuner the 520 for maximum smoke on SSB with thee "DX" switch off and dial the power down to 30-40W PEP output. The rig was happy, it produced spectacular IMD numbers so the PSK neighbors either side of my signal were happy, I was happy.

I've been thinking about buillding the HB 250/300W SS amp. The instability it experienced on 80m was due to it's marginal power supply that would current limit at 300W on that band. Feed it wuth a stiff 50V 20 amp power supply and it should be golden. The LPF in that amp is a work of art. -60dB HF and -70dB 6m harmonics. The IM3 measured -38 dB.



On Sun, 24 May 2015 21:46:19 -0700
"Jim Thomson" <jim.thom at telus.net> wrote:

A method to get around the ALC induced imd, is to use external 0 to –7 vdc  alc volatge, then feed it to thre xcvrs  rear alc input.   That way you can dial up any PO you desire, and not have to develop alc voltage..after the fact.  A simple setup with a 9 vdc battery feeding the outer ends of a  50-100k pot  works great.    The wiper and one end is the V divider  supplies the 0 to –9vdc to the alc jack. If you want say 65 watts pep.... just set the PO control on the xcvr to max.....then adj the alc voltage to 65 watts pep.  Done deal. 
Scream all you want, with mic gain cranked up..and wattmeter never goes higher than 65 w pep.....or what ever you set it for. 


-- 
R. Kevin Stover
AC0H