| Author |
Message |
    
Stealman
| | Posted on Thursday, December 25, 2003 - 3:50 pm: | 
|
hi i new to the form could sone one tell what does grid tune on a d&a maverick 250 do |
Spiderleggs
| | Posted on Monday, December 29, 2003 - 7:11 am: |
|
It is used to match the radio with the amplifier or it sets the swr between the radio and amplifier. |
2600
| | Posted on Tuesday, December 30, 2003 - 2:24 am: |
|
Hi Stealman,
Place a SWR meter and extra coax jumper between the radio and the "radio" socket on the amplifier.
Tune up the amplifier for max modulated power, and then check the INPUT-side SWR. Turn the grid tune, while you are keyed, watching the SWR side of the meter. Turning the Grid Tune, you will see the SWR fall to a minimum, and then rise again. They call this a "dip". It's just the opposite of a meter "peak".
You will also see that turning the Grid Tune screw affects the output power on the wattmeter. Typically, the Grid Tune will show a peak on the output meter at one spot, and a dip in the INPUT SWR at another spot. A compromise setting between the two spots should not reduce the output swing by much more than 10%, and should get the input SWR below 2 to 1. Much higher than that could be unhealthy for the final in the radio.
In a perfect world, that minimum INPUT SWR spot and the output power peak would occur at the very same setting of the Grid Tune. If the two settings are too far apart, that indicates that soldered-in stuff inside needs to be molested.
73 |
Stealman
| | Posted on Friday, January 02, 2004 - 7:32 pm: |
|
thank for the info |
|
