In a message dated 15/01/05 23:36:15 GMT Standard Time, [EMAIL PROTECTED] writes:
I know there was a recent discussion in the forum about this birdie singing at the low end of the 10m band, but did not recall seeing any definitive way to kill it. In my case, I want to think of the birdie living in my K2/100 as a substantially bigger one, a turkey (with the K2100 enabled -power >11w) at 28.266 (USB), Signal strength S2 with the preamp enabled changes to .... an Ostrich (think logarithmically) of a solid S5 !!! at 28.264 when disabling the 100W option. ------------------------------------------------------------------------------ ----------------------------------------- As a benchmark with the antenna socket terminated, i.e. no external antenna connected, the only birdie of any real significance with my QRP K2 #4168 is at exactly on 28.000MHz. This is exactly where it should be as the 7th harmonic of a correctly adjusted MCU 4.000MHz clock for U6 on the K2 Control board. There are other birdies between 28.000 to 29.000MHz, but are so feeble that they fall into insignificance and none of them move the S meter at all even with the preamp on. This is with a receiver that gives S9 on 28.200MHz at 50uV PD with the preamp *off* and meets the MDS spec for the K2. I am aware of the birdie at 28.000MHz as that clashes with a band edge beacon I receive via an external VHF transverter. Even with this present it is possible to copy the beacon down to an extremely low level with the K2 preamp on. The reported birdie at 28.276MHz is there, but extremely faint at about 28.275.6MHz on USB and shifts up to about 28.277.7MHz on LSB. I would think it fair to comment that most ham receivers have birdies somewhere if you want to try hard enough finding them. With what I have found on my particular QRP K2 it may be a good idea to remove all the various options added to the offending K2's and go back to basics to see what the effect is then. Once that test is sorted out the gradual addition of the various option boards should find the offending one(s) to enable a solution to be sought. There or no turkeys or ostriches in my K2! Bob, G3VVT K2 #4168 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
