I found one place in this tech ref (NAVSHIPS 0967-063-2010) that gives a clue to the relation of microvolts fed into the balanced antenna connection and the c/l meter reading, and that's on page 5-21 at item 17 in the TABLE 5-5, TROUBLE ISOLATION. Briefly, it says that a 10 uv input should read 40 db on the c/l meter and a 100 uv input should read 60 db on the c/l meter.
Unfortunately, that is not true, 10 uv should read 20 db and 100 uv should read 40 db. The relation of 'uv in' to 'c/l meter reading' is quite simple: as the uv input level is multiplied by 10, the c/l meter db reading is increased by 20 db. So, 1 uv = 0 db, 10 uv = 20 db, 100 uv = 40 db, 1,000 uv = 60 db, 10,000 uv = 80 db, and 100,000 uv = 100 db. A nice clear graph of this relation can be seen in the tm-11-856a r-390a tech ref on page 75. Here's a link to this tech ref on our website: TM-11-856A.pdf (r-390a.net) <https://www.r-390a.net/TM-11-856A.pdf>. In my experience, the c/l meter normally works as described in the tm-11-856a r-390a tech ref when the AGC and c/l meter circuits are working as designed. Regards, Larry ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
