Nope,? you? got it? ass backwards.? Measure? the plate? block? cap? current if u don't? believe me.? W8JI, W8ZR, and John? Lyles? also? concur.?
At? 29? mhz,? the anode? to? chassis? capacitance? becomes? most? of the resonant? tank? capacitance.? ?How? do u? ?think? the main? tank? coil? gets? connected? to the tube? C.....? via? the? plate? block? cap of? course.

If the plate? block? cap is? installed at the 50? ohm? end? of the? PI /? PI-L? network,? then? u? end? up? B+? on? both? the? tune +? load? caps, tank? coil(s),? bandswitch,? roller? coil? (if? used).? It? would? work, but? u just? added a ton? of? stress to? all? those? aforementioned? tank components.?

Those? 4-5" (100-120mm)? diam? 'puck'? style? caps? won't? handle 142A? like? 4 x? 250? pf? HT-59's? will.? ? Even? the? ?140-150-200-205-250 mm? 'puck'? style? caps? won't work.? ?Trying to parallel 'puck'? style?caps? is an? exercise? in? futility.? 2 x 200mm? pucks eats? up? ?8" x 16.5" !?

As? Carl? noted,? the? Centralab? 859? /? HEC? HT-59? is only? 2.25" diam? x 3" long.? ?I mounted? 4 x HT-59's? on a 3" x 3"? x 1/4"? thick? piece? of? copper..? (used on a single 3CX-20,000A7, 27 mhz amp).
4 x HT-59's? are? good? for 25 kv, 142A? CCS,? and? 200? KVA....? and? 1000? pf? total? C.? ? Good? luck? trying? to? find a? puck style cap that? remotely comes? close? to? those? specs... they? don't? exist.?

The? 'kva'? rating is? typ a non? issue.? ?Knowing? the capacitance? of? each? block? cap, the? XC? of? each? block? cap? is? easily? calculated.? ?We already calculated? the? current through? each? block? cap.
Current? x? XC? =? AC? Vdrop? across? each? cap...which? is? typ? a?very low? value.? ?The? AC? V? drop? +? any? bias (B+)? can't? exceed the block? cap's? stamped? V? rating.? ??

The? AC? current? through? the? block? cap....? x? the AC? Vdrop? across? the? cap = va power.?

Using the? 2 x 3x15 tubes on? 27? mhz? for the? following? example.?
250? pf? = 23.59? ohms.?
100.93 A? /? 4? =? 25.23A? PER? each? of? the? 250? pf? caps ( 4 x caps used? in parallel.)?
?23.59 ohms? ?x 25.23 A =? ?595 Vac? across? each? ?of? the? 4 x caps.?
595 vac? x 25.23 A? = 15,012? VA? ?( 15 kva)? Per? cap.
Each? cap? rated? for 50? kva...so? within? spec.?

On low? bands,? like? 160 ,? ?XC? per? cap is a lot? higher, but cap? current? is? very? low....so? it's? still a non? issue? as? far? as KVA? ratings.?

Download? the? HEC catalog.? ?It? depicts kva/current / voltage vs freq? in? graph? form? ?I? will? post? the? HEC Catalog on? this site since,? since I? have it already? in PDF? form.? ??

Jim? VE7RF??

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