Probably the "inj" level is higher from the T4X. Might need to investigate the R4B mixers.
JB From: [email protected] [mailto:[email protected]] On Behalf Of J G Sent: Thursday, 10 November 2011 9:29 AM To: [email protected] Subject: [Drakelist] R-4B low sensitivity low output on 10 meters 28 MHZ Hi, Now that 10 is alive and well, I decided to put the B line (T-4XB, R-4B) on 10. Hasn't been there in a long time. The low sensitivity part: The R-4B has low sensitivity on 10. I do not recall that from 20 some years ago when I was last on 10 with it. Using the R-4B to control, the calibrator will get an S meter reading of about S5. Using the T-4XB to control the calibrator will yield an S8 reading. This was done at 28.5, and this is after adjusting the 4 trimmers for 28.0. I notice the same results using the cw range (28.0 - 28.5) crystal at both 28.0 and at 28.5. I do have 28.0 and 28.5 crystals in both the R-4B and the T-4XB. A low S meter reading is also obtained using the 24.5 meg crystal that I have in an accessory socket of the R-4B (I do not have one for the T-4XB). As expected, "real signals" are louder using the T-4XB to control. This situation did exist on 15 meters, but adjusting the 21 trimmers did take care of that. The low output part: Using the R-4B to control, power out is low. About the best it can do is 30 watts with .16 plate current. Using the T-4XB to control (transceive), about 75 watts with .26 plate current (gain full open) Using the SEPARATE position about 110 watts with .32 plate current (gain at a bit less than 12:00) Power readings as per wattmeter in C-4, so may not be accurate, but they are relative. I think the low sensitivity and low output problems are related, but I am not sure why the output would vary so much between the T-4XB as the transceive control and the separate control. Any ideas welcomed. Thank you, Jim
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