The AM Forum

Operating the SB220 yesterday AM with K2RP on 20, unkeyed and all of a sudden the plate meter PINS, master breaker to the station trips (which makes me wonder about those wonderful breakers in the back of the 220, but that's another story)....

Iplate meter PINS, HARD, I was actually standing over the amp when it faulted, slight sparkley lightshow internally.  Bypass the amp until today, rip it apart.

Found out the 1000 pF bypass cap between RFC2 and RFC1 is measuring 70 ohms.  Welp, that will pull an amp at 2800 volts! :)

My problem is this:  NOBODY has a doorknob locally, and I'd like to use the amp in the contest this weekend.  It's a REAL bummer going from 800-1200 watts BACK to 110. :(

Maybe I should title this:  HOW many radio shack .1s would I need to series parallel to equal this cap, short term, while the new one arrives?

I'd throw the Harris RF-103 in line, but with the 4-1000 conversion from the 3-1000, the tuned inputs are WAY out of wack...  Only good for tube output xmitters :/

Anyway, any ideas on JSing this cap for a few days while I source a doorknob for it?


--Shane
KD6VXI

Actually, I just looked at the Shack, and it looks like the biggest they have (V rating wise) is 500 volts....  I can't see stuffing 36+ caps in trying to series parallel this.  Screw it, qrp for the week :(   

   Shane, Any chance you have a local ham nearby with a real old time "junk-box", or maybe an Ameritron linear that is "crapped out"? Also the 11m gang might have some "good-buddy" carcasses laying in the heap.

Jim
WD5JKO

Use a .001/6KV disc, works better at RF than that TV doorknob in it. Also use a real RF cap at the plate blocking before you lite something else up :o

I can send you a coupla disc freebies.

Carl