well I don't have all of my notes right here in front of me but let me tell you what I can remember right off the top of my head.
#1, your doing the right t hing shotgunning all of the caps, regardless if they are paper bypasses, ceramic disks, or electrolytics. Thats an important first step. Now.. look on your schematic at the output section. They use series/parallel silver mica's to come up with the output loading caps. These are notorious for going bad on you. If they don't just fail right off, th ey can do squirrely things to your output loading, cause rf spurs in area's where you don't want them, and, if they fail, can actually take out the rf choke that is in the B+ line and etc. Those damn things are receiving silver mica's rated 500v each. Barely adequate, if that. Why Johnson did this I will never know. One of the series/parallel combo's adds up to 330pf and one adds up to 150pf ( I think ). Replace each of these with a SINGLE 3000V or 6000V transmitting mica. You can get them from Surplus Sales in Nebraska. They are not cheap, but what price for replacing a lot of other stuff that can be burned up if those originals fail? You will have a small difficulty finding room for these big caps, but you can do it. I did. Also, there is another little cap that is multi section in there, total capacitance is 1200pf. I have never had one fail but it could. Just look at it real good. Okay.. the VFO.. its a bitch to get into BUT.. you want to pry it open and remove that bastard 18K 2 watt resistor. You want to add a small solder stip somewhere under the chassis, right beneath the VFO and tie a new 18K 5 watt ceramic resistor, across the solder strip, with one end of the resistor soldered to the ground lug that attaches the solder strip to the chassis. Then run a wire from the other end of the new 18K resistor ( the end above ground ) to the point inside the VFO where the original resistor was hooked up. That factory resistor is well known for failure and when it goes, it eats up all kinds of components in the VFO. Its well worth the trouble to move it out of there, plus, it takes some heat out of the VFO. Tubes. don't put 6146A's, B's or W's in your Valiant. It was designed around plane jane 6146's. You can still get them. I have the name of a fellow at home somewhere, down in florida that will sell you amperex 6146's for a very good price, brand new in the boxes. The modulation section especially likes them, and the RF will be much easier to neutralize with these. Examine the bandswitch real well, as well as the switch that switches capacitance in and out of the output loading. Look for carbon traces. If they are there, on the ceramic, scrub them off with a pencil eraser IF you can get to them. If not, get it off the best you can. And WHILE you have the beast out of its cabinet, clean all switches and controls with De-Oxit. after you get everthing changed out, neutralize the rig, and set the idling modulator current as per specs in the manual. DON'T PUT THE SCREWS BACK IN THE CABINET UNTIL YOU HAVE RUN IT A WEEK OR TWO.. LOL man.. its a bitch to pry it out of that cabinet when all the screws are in it, and you can visually see fire inside ( this happened to me when a modulation transformer shorted to ground ). Valianta are not operator freindly. I love them, they are good radio's but if you don't want to be working on a radio a lot.. a valiant is not a good rig to have. Its not as reliable as a Ranger. But its a damned sight better than a DX100 or Apache LOL good luck with your rig and holler at me if I can help in any way. Ronnie On Fri, 26 Sep 2003 13:35:16 -0500, Anthony W. DePrato wrote > hi Ronnie: > would love to get your ideals on the Valiant. got my caps ordered > today.. only $65.00 worth to replace all the eletro's and .005 > disks. 40 of those . wanted to do it right when i put it on the > bench.. btw i may have another one next month.. if things work out. > 73 Tony wa4jqs > > _______________________________________________ > AMRadio mailing list > [email protected] > http://mailman.qth.net/mailman/listinfo/amradio The "AM" voice of Shreveport, Louisiana USA formerly WN5AIA and WB5AIA I got my Extra Class the old fashioned way... I earned it!
