John, My DMM is a $30 Radio Shack unit. I do not have anything handy to calibrate or check the accuracy. It does report DC voiltage to 2 decimal points, but I doubt that it is that accurate. Any way, for now I'm proceeding with construction.
Mike, W8ENG ----- Original Message ----- From: "John R. Lonigro" <[EMAIL PROTECTED]> To: "Mike, W8ENG" <[EMAIL PROTECTED]> Cc: <elecraft@mailman.qth.net> Sent: Tuesday, November 16, 2004 10:29 PM Subject: Re: [Elecraft] Low voltage on AGC threshold > Mike: > > How accurate is your DMM? The 8v and 5v regulators should still produce > 8 and 5 volts even with a slightly low supply voltage. Also, if the > K2's internal voltmeter reads the same as your DMM, that tells me your > DMM is reading low because there is a diode in the K2 power line which > will make the K2 internal voltmeter read LESS than an accurate external > DMM. Only if the external DMM reads low would the two voltmeters agree. > > Try to check your voltages with a different DMM. My guess is your > problem is NOT low voltage all around. Good luck. > > 73's > > John AA0VE > > Mike, W8ENG wrote: > > >This is an update to my earlier post. I touched up a solder joint and > >reassembled the radio. The voltage on pin 5 of U2 was still 3.78 volts, > >with the RF gain set fully clockwise. The input voltage from my power > >supply was 12.4 volts, both on my DMM and on the K2's internal voltmeter. > >The voltage out on the 8v regulator was 7.8,a nd on the 5v regulator was > >4.9. > > > >I'm thinking that the problem may be low voltage all around. I don't have a > >better power supply to check with at a higher voltage. > > > >Any addational help or comments would be appreciated. > > > >73, Mike, W8ENG > > > > > _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
