My recollection is that the Valiant was also limited by the design of the iron used in the audio driver stage. But as mentioned, back in the day 'punch' was the name of the game, not smooth fidelity. This can clearly be seen also in the venerable Collins KW-1 which, while perhaps the overall highest quality transmitter of the day has several weaknesses in areas like the audio driver circuit as well as restricted audio overall. Interestingly, the models in roughly the first half of the run had nicer audio, but apparently Art wanted the transmitter to cut through the QRM (heterodynes) better so some simple changes were made, like tightening up the values of coupling caps. Just going through and fattening them up helps out tremendously, as does swapping out the grid input resistor in the mic amp (1M) for a 4.7M or higher value. Fatter electrolyitics will help out with the lows as well, but at the end of the day it will take a rebuild of the audio driver (6B4G x 2) to 4 tubes and some other tweaks to really drive those 810s. Not worth the bother IMO. Easier to find or build something else and enjoy the old rig as it is with just the simple changes to smooth things out, including bypassing the clipper.
~ Todd, KA1KAQ/4 On Wed, Sep 16, 2009 at 7:34 AM, Bry Carling <[email protected]> wrote: > Charles - that would probably be due to the nasty 6AL5 clipper circuit > used in the Valiant. > > It would affect the audio badly even when turned all the way down. > > ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: [email protected] To unsubscribe, send an email to [email protected] with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
