Looking for feedback. Dumping info and my understanding. I got some remote temp sensors hooked up to a serial port (QK145 kit) and wanted to investigate temps on my AL1200 during RTTY contesting. Imp
Thanks Bill. I've read some of your comments in the forum on the AL-1200 before. I think one of the good things we can do as users is to just document what happens in as much detail as we can. There
Bob K6XX commented on watt reading accuracy on the AL1200. Yeah, I knew someone was going to say "get a Bird!" :) I did run the coax thru my Palstar AT1500 tuner in bypass mode before it went to the
Ah! good info Bill. Yes this is much more severe than my proposed 50% worst case duty cycle. (i'm not sure my dummy load can handle that duty cycle for long...) I might try that duty cycle it at 1200
Thanks for the info, Jeff. You mentioned the tube temps..., the 3CX1200A. I had looked at them, and had some questions so I'll take the opportunity to throw them out here... The full datasheet is her
Thanks Bill. I'll check that out. I would note that a higher speed blower has already been done by people for the AL1200, and has been mentioned on this forum...i.e. I'm not inventing something. I wo
I must have fried something in my AL-1200 and would be interested in thoughts. Details: Was operating on 15M, rtty, when it died. I watch temps with an infrared thermometer so I wasn't expecting to h
some more info -swapped amp out with al-80b during contest..everything fine, so cabling etc not an issue. Tests are into dummy load. -756 pro II drives the amp. With the rig's auto-tuner off, swr is
Billy, AA4NU and Gerald K5GW both I guess asked the same question.. do I see any plate current due to bias when the amp is keyed to transmit (even if no rf in) I'll check that again tonight. My recol
Hal W5GHZ suggested: "Check out the two Zener diodes above the filament transformer mounted on the wall. The high duty cycle may have burned out one or both." Other people seemed to point in the same
Boye posted from a search "Zeners was replaced too to a 50W type and 2A fuse insert to cathode DC connection" This is interesting because I was also looking at the 50W zeners and wondering if the 10W
Carl: "There is an ample front to rear aluminum shield that is more than adequate to dissipate the 8W or so in normal use." All heat gets dissipated eventually. The question is: what is the junction
Good info Ian. I was looking around trying to learn more about the various bias circuits in use. maybe people can provide historical views on some things I was curious about: -This 1971 Eimac paper o
A big thumbs up! I want to give everyone on the reflector a big thank you tonight..A bunch of people gave useful comments, some in direct email: Carl KM1H Bill W6WRT Hal W5GHZ Gerald K5GW Alek VK6APK
ok, dumb question but I can't find a schematic, and there seems to be nothing on the web. There are 6 holes in my al-1200 for apparently adjust the slugs on the coils on the input tank circuit. I've
Ordered on 10/25/10 At my doorstep 11/9/10 Denys on ebay. he combined shipping for two buys. Shipping was $12 USD. $24 for 4 NOS 330pf 4kV 15kVAR and 2 NOS 1000pF 12kV I'm impressed that I can click
I just got done redoing the input network on my old FL2100b (adjust 15m/10m coils and caps) and was happy with the result..so I went back to the AL-1200 I've mentioned here before to fix it's issues.
thanks everyone for all that. I notice in the user manual, it does show extended freq ranges to include all the WARC bands except 24.5 Mhz. 160M: 1.8-2.0Mhz 80M: 3.3-4.4Mhz 40M: 6.3-8.3Mhz 20M: 9.5-1