On Mon, 1 Dec 2008 16:30:23 -0600, [EMAIL PROTECTED] wrote: >I've got a TR7A that works good on SSB, but AM transmit is problematic. I >have to keep changing the carrier level control to get it to work. I've >cleaned the control and aligned the radio, even changed a couple of caps >to get the 40mhz oscillator and BFO both "dead on". It also acts >different from dummy load to antenna (only on AM). Anyone else had or >have a similar problem?
I haven't seen anyone tackle this yet, so I'll take a stab at it. Under what conditions do you have to change the carrier level? Band change, frequency change, antenna change, SWR change, etc? The amount of carrier that you need is dependent on the PEP output level that is available in SSB mode. This level is determined by the ALC circuit. ALC is derived from the forward and reflected power sensors for the built-in wattmeter. Anything that changes the output levels of the wattmeter sensors can change the ALC level and the maximum PEP power available. It will tend to vary by band and antenna SWR. So, some change when operating parameters change is normal. If it is changing from day to day on the same antenna, band, and frequency, you may have a problem somewhere. Hope this helps. 73 -Jim NU0C _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
