Recently picked up a refurbished 19 set New 9/59 , with the B Set removed . The output on R/T is very high , about 15 watts , it looks completely untouched , as is the psu . All my other sets have only ever put out 2-3 watts in R/T . Anyone ever experienced this ?

Do you own a serviceable 19 Set? yes

Hi Mark

Did you ever get a reply? I have a problem where I get the same output on AM as I do on CW,this shouldn't be the case from what I read in the manual. I had a problem where I could only get 1.7 W out, this turned out to be an O/C R in the TX ALC CCT.R18A.

Would be pleased if anyone had an Idea why I am getting same output on AM as CW!

73
Ian G4GIR

Do you own a serviceable 19 Set? YES

The No 19 set is limited in output by the 6h6 diode in an somewhat unusual but simple drive limiting circuit. The EF50 tube wonderful as it may be is unable to overdrive the 807 final so one must assume it was done to limit range and maintain stealth during ops. Casterating the 6h6 by leaving its heater circuit but eliminating the other functions takes the no 19 from a 6 to 8 watt AM radio to a almost 20 watt Am rig instantly. No other work is required. It could also be done in the circuit and it is not impossible it could happen as the resistors in these set wander in values like nothing else I have ever seen (IE meter resistors for instance. The set will modulate well and its range will reach 400 to 500 miles plus on AM in normal conditions. when this mod is done or condition exists.

The set I used to win the 2016 Antique Wireless Association I intentionally did this too. It changes the whole ball game and the need for a linear becomes much less of an issue for normal ops. My 19 set appears to be more effective then say my DX60B Am rig after this mod. Probably because coupled with the type of modulation the No 19 has it is much more effective. It is possible that has been done to your sets as it requires no internal work to do. A sharpe experienced operator in the field even back in WW2 would have been able to figure this out too and deal with it. A wise one would have done it and said nothing. It took me about a year of thinking and looking at the schematic to figure out what they had done to limit output.(despite the fact that many said i was nuts to expect decent output from an 807. Fortuntely since I am from that era and have several other transmitters using its cousin the 1625 (12v 807)I knew better.)

Anyway either by plan or by accident the drive level in you sets is probably now at a decent level and not choked back as they were from production in AM mode.

don

Do you own a serviceable 19 Set? yes