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THE AM BULLETIN BOARD => Technical Forum => Topic started by: ve6pg on June 26, 2007, 12:03:46 PM



Title: dx100--no load on 10
Post by: ve6pg on June 26, 2007, 12:03:46 PM
...hi from tim...my dx100 is werking ok fine on 160/75/40....10 is open, and tried to tune up....plate current nearly off the end, swr is gud...the grid current can be brought up, but i cant dip the final...the result is blown fuses....any thoughts?....sk...


Title: Re: dx100--no load on 10
Post by: WA1GFZ on June 26, 2007, 12:13:32 PM
check the 10 meter contact on the final tank switch which may be open or dirty.


Title: Re: dx100--no load on 10
Post by: ve6pg on June 26, 2007, 01:12:00 PM
...when bandswitch is in the 10 m position, i do get read-out on the freq counter, as say, 29100, etc...if the bandswitch wasnt connected, i doubt i wud see the read out..strange...the zero bead is rough sounding, not like on the lower bands.....sk....


Title: Re: dx100--no load on 10
Post by: Pete, WA2CWA on June 26, 2007, 02:02:27 PM
Work on 20 and 15?
Using a 50 ohm dummy load?
Too much loading cap. on 10?
Did it ever work on 10?


Title: Re: dx100--no load on 10
Post by: WA1GFZ on June 26, 2007, 02:05:19 PM
The final tank could be messed up and still enough energy to drive the counter ??? Or the final could be oscillating.


Title: Re: dx100--no load on 10
Post by: ve6pg on June 26, 2007, 02:30:33 PM
...ok...it loads on 20/15...never tried it on 10 before..always down lower...50 ohm dummy, alot of cap to to tune it....as i said, very poor spotting carrier,..strong, but not clean....sk...


Title: Re: dx100--no load on 10
Post by: Mike/W8BAC on June 26, 2007, 02:42:44 PM
Crystal or VFO? Sounds like an oscillator problem. Scope the oscillator.


Title: Re: dx100--no load on 10
Post by: N3DRB The Derb on June 26, 2007, 05:04:07 PM
maybe coarse loading control not on 9~10 (all the way clockwise) and load with the fine red control starting from zero??

cant be the osc, something is driving the plate current off the scale. it's getting drive. What needs to be verified is it on the right band/freq? and are the finals neutralized on 10M? need to verify 6146's are, by disconnecting plate voltage to both tubes ( leave he plate caps on.)  and checking to see to your grid drive changes when you rotate the plate tuning control. goal is zero or little change in grid drive. Adjust ur neutro wire in your final cage until this is so. with no plate voltage on the finals. unsolder that HV red wire and tape it off.


Title: Re: dx100--no load on 10
Post by: ve6pg on June 26, 2007, 07:06:47 PM
...using the vfo..gonna try it agn tonite...lost my nc300 dis afta noon...xtreme hum, regardless of volume...gonna put the sx25,or the hq129x in line...when it rains...(wait a minute, i need rain here)....sk...


Title: Re: dx100--no load on 10
Post by: N3DRB The Derb on June 26, 2007, 11:09:38 PM
one of ur filter caps blew up on nc 300. replace them all as long as you gotta go in there. I think it's a big twistlok job.
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