Hi John: from I can gather, it appears that National did this same thing with at least several other rx. 6h6s are cheap, but a fast diode would work fine if needed. National had to have a reason for this, s-meter zero can be taken care of in many other ways. 73 Bernie ----- Original Message ----- From: "John Coleman" <[email protected]> To: "'Discussion of AM Radio in the Amateur Service'" <[email protected]> Sent: Thursday, December 17, 2009 7:15 PM Subject: Re: [AMRadio] HRO question for the day
>I can see a small amount of contact bias being generated by the 6H6, 6AL5, > etc. But that would be easy to compensate with divider from the cathode > bias of the output tubes or any small positive source. I guess they may > have been looking for an easy fix to get the S-meter to zero. > This is all very interesting but why not just solder in a Germanium 1N64 > or > a NTE109 or Silicone NTE177 or even a NTE519 with 4 ns recovery time. I > pulled the 6AL5 out of my HQ170 and went to diodes. Saving 150ma of heater > current WEEEE. > I ask this sincerely because I really don't know. > What would be the disadvantage of using small signal solid state diodes as > long as the IF frequency isn't too high. > John > > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
