Question about Ameritron AL-1200 Amp (Uses one 3CX1200Z7 tube)
I have a Ameritron AL-1200 brought to me by the KN4UNA, P.J., who received the amp from his uncle's estate (W4WWF Dale Mash SK) and it has a problem with giving a arc when the power switch is first
By
Cliff Fox (KU4GW) <cliffku4gw@...>
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#37108
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Re: Plate Blocking Capacitors again
The Marconi transmitter at BBC Wooferton used a water cooled vacuum
capacitor 1nF 44kV as a coupling capacitor.
By
Peter Voelpel
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#37107
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Re: Plate Blocking Capacitors again
shoulda? read...... with the? application? of? DC.
Jim VE7RF
By
Jim VE7RF
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#37106
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Re: Plate Blocking Capacitors again
Yes? I? realize? 95%? of? MW? these? days? are? SS......? I? was? referring? to the? older? tube? pa.
Fixed / variable? ?vac caps? have? to? be? severely de-rated? for plate
By
Jim VE7RF
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#37105
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Re: Plate Blocking Capacitors again
a linear fo AM is just a bad idea. They are 25% efficient at best. AM broadcasters largely gave them up 80-90 years ago. The Doherty version is a much more efficient option but still less efficient
By
W2XJ <w2xj@...>
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#37104
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Re: Plate Blocking Capacitors again
sw broadcast TXs use vacuum caps. MW transmitters are all solid state except for the very old ones. SW TXs 50KW and under are also mostly solid state these days as well.
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W2XJ <w2xj@...>
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#37103
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Re: Plate Blocking Capacitors again
He's? got? it? mounted? on a piece? of? fiberglass.? ?He? shoulda? used? nylon? screws? to? mount the? fiberglass to the? rear? wall....and? also? another? pair? of
nylon?
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Jim VE7RF
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#37102
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Re: Plate Blocking Capacitors again
I? went? through the? entire? pdf.? ?They? state the? mica? caps? are? designed? for? 100? khz? to? 3? mhz..that's? it.
Then? the? graphs? depict current? ratings? from?
By
Jim VE7RF
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#37101
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Re: Plate Blocking Capacitors again
Interesting that he uses one of the 'Millen HV connectors' that are
supposedly only rated at 2500VDC to bring his 6500VDC in!
Mod-U-Lator,
Mike(y)/W3SLK
From: [email protected]
By
Mike Sawyer
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#37100
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Re: Plate Blocking Capacitors again
Not always:
https://www.cde.com/resources/catalogs/HVOLT-CYL.pdf
73
Peter
_____
From: [email protected] [mailto:[email protected]] On Behalf
Of Jim VE7RF
Current
By
Peter Voelpel
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#37099
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Re: Plate Blocking Capacitors again
I'd be? more? worried? about? the? current? rating..vs? V? rating.? ?What? bands are? you? planning? to? use..and? what? tube(s) ?? ?If? u? are? using? tubes? with? typ
By
Jim VE7RF
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#37098
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Re: Plate Blocking Capacitors again
Many thanks for that Peter.
At 10kV peak working that capacitor looks to have a much lower rating than mine.
73s Tracey G5VU
By
Tracey Gardner G5VU
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#37097
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Re: Plate Blocking Capacitors again
Seems to work
https://www.qsl.net/kf8od/3cpx5000.html
73
Peter
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From: [email protected] [mailto:[email protected]] On Behalf
Of Sharalyn Koeppe
Sent: Sonntag, 19.
By
Peter Voelpel
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#37096
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Re: Plate Blocking Capacitors again
I have understood that mica is not suitable for plate blocking due to dielectric migration from the DC applied.
73,?? Roy??? K6XK
By
Sharalyn Koeppe
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#37095
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Plate Blocking Capacitors again
I have an 1100pf large block shaped Dubilier mica capacitor dating from 1944.
It measures approx. 3.75w x 2.25d x 3.25h inches
It states on it that it was tested as follows
(a) 6 amps at 300kHz for
By
Tracey Gardner G5VU
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#37094
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Re: Interesting High Voltage capacitors
OK, I? downloaded? the? entire? catalog on? that? series.? ?Most? are? rated? at? c 100 Amps? of? ripple? current....? but? at? lower? ambient? temps.? ?Per? cornell? dublier?
By
Jim VE7RF
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#37093
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Re: Interesting High Voltage capacitors
Re[2]: [ham-amplifiers] Interesting High Voltage capacitors
Friday, January 17, 2020
In an RF amp where might be appropriate to use Teflon capacitors?
Best regards,
Chris 2E0ILY
By
Chris Wilson
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#37092
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Re: Interesting High Voltage capacitors
Those are DC link Capacitors. I have used them for years now in amplifiers. Not that brand though.? I used the 944U. They make them up to 1.4KV at 70UF.? Or 1.2KV at 100 UF.? That is full working
By
W7WRX
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#37091
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Re: Silly as it gets
G'Day Jim,
You made a very good post to round-off this entertaining thread of posts
largely by Ned Flanders type insufferable puritans.
My other two takeaway quips from the most amusing read
By
Leigh Turner
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#37090
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Re: Interesting High Voltage capacitors
I? downloaded? their? entire? catalog? in? that? series.....4? days? ago.? ?Now? I'm? having a helluva? time bringing? it? up.
Can't? remember? if? they? stated? ESR at?
By
Jim VE7RF
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#37089
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