I thought that the WRL DuaoBander mobile was only SSB. On 22 Nov 2004 at 22:11, John Coleman, ARS WA5BXO wrote:
> My experience (which is very little when it come to these sweep tube > rigs) is they or rated for a belch or some thing short and don't hold up > to a fix channel field day adventure with out tube replacement. I had a > DuaoBander mobile for a while rated a 400 watts PEP input I never saw > more than 150 watts output while whistling in the mike. It was in > perfect condition and would light a 50 watt bulb with normal speech. I > thought it would have blown it out. I was very disappointed. Yet, it > was one of the most heard radios all over the country by many AMers in > the late 80s. > > > John, WA5BXO > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Brian Carling > Sent: Monday, November 22, 2004 9:55 PM > To: Discussion of AM Radio > Subject: RE: [AMRadio] AM Usage with Linear AMPS > > Aren't there a lot of commercially built amateur radio linear > amplifiers and RF finals that exceeded he manufacturers MAX > Pdiss rathings over the years, by adding a COOLING FAN to take > away the extra heat? > > One thinks of MANY sweep tubes rated for so-called Pdiss of 16 > watts and 20 watts that are regularly run at hundreds of watts of > RF! The tubes don't seem to melt. > > I think of the ubiquitous 6JS6C with a rating of 30 watts. > Yaesu ran a pair of these at 260 watts input in their FT101 series. > Many guys ran them at 260 watts p.e.p. on SSB and 260 watts CW. > Assuming 65% efficiency, you have 35% of 260 watts going into > the plates. That is to say 91 watts split between the two tubes. > UH oh - POP! But no, they didn't. > > Then when you throttle that FT-101 back to 40 watts input on AM > and go to your 30% efficiency (if it is) then you are actually > putting only 20 watts carrier per tube which is SAFER. > > Is that correct? > > How about some of the othre rigs that rated their 2 sweep tube > finals for 560 Watts or even 800 watts!? > > Then youhave peak Pdisses of 140 to 200 watts between the two > sweep tubes, most of which are rated for no more than 40 watts. > > > > > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected]
