More QRO secrets revealed.... 15 -20 kw baluns !!
I couldn't resist. To make a 40-10m choke balun for 40-10m yagi's use type 43 beads [1" OD x .5" ID x 1" long] slid over RG-393 teflon coax. The balun is 17" long when completed [16-17 beads.] The Z
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pentalab <jim.thomson@...>
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#162
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Re: HIGH SWR / HIGH REFLECTED POWER SHUT DOWN CIRCUIT !!
it's just as easy to build a big one as a small one. ##### Use a cum-a-long hooked to a basement beam... or one of those small devices used to lift small engines. Me... after tearing the crate
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pentalab <jim.thomson@...>
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#161
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Jumbo sized lytic stack for HV supplies ! Oil cap warning. DIODES
If any of you intend to series parallel Oil caps for greater V ratings... BEWARE. I did just that with 4 x 50 uf @ 4500 V units. These were each 12" tall x 8' wide x 4" thick. I got em years ago from
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pentalab <jim.thomson@...>
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#160
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Re: HIGH SWR / HIGH REFLECTED POWER SHUT DOWN CIRCUIT !!
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R L Measures
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#159
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Transformer info on Wikipedia
All, I started editing the page on transformers at Wikipedia at 6:00 PM this evening, and it is now 4:30 AM in the morning. I corrected a few errors from others plus added a complete section on steel
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craxd <craxd1@...>
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#158
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Re: HIGH SWR / HIGH REFLECTED POWER SHUT DOWN CIRCUIT !!
the like. Some pics of your "QRP" amps (They also make the usual 10 kw 5 kw.. 2.5 kw qrp slugs.) would be very much appreciated. ### Tnx Dick..... As soon as I can figure out this pix posting deal...
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pentalab <jim.thomson@...>
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#157
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Re: HIGH SWR / HIGH REFLECTED POWER SHUT DOWN CIRCUIT !!
Great info Jim! NOW we're talking amplifiers ;-) Thuis yahoo group has the possibility of posting pictures, files and the like. Some pics of your "QRP" amps (They also make the usual 10 kw 5 kw.. 2.5
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PA3DUV <pa3duv@...>
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#156
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HIGH SWR / HIGH REFLECTED POWER SHUT DOWN CIRCUIT !!
wrote: full ### Peter, et all ### I had an engineer buddy of mine cook up a high reflected power shut down circuit for me. My buddy got a hold of a ton of Bird single line sections. He joined two of
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pentalab <jim.thomson@...>
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#155
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Coaxial Dynamics now makes a 25 kw slug for a 7/8" line section !!
Gents This may well be old news to some... but Coaxial Dynamics makes a 25 kw slug.[2-30 mhz].. for a standard 7/8" line section....cheap. They also make the usual 10 kw 5 kw.. 2.5 kw qrp slugs. It's
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pentalab <jim.thomson@...>
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#154
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Re: "New" method of fabricating a better chimney
wrote: use a full ### Partially agreed. ..BUT the 3CX-6000A7 is rated at 3.5 A of plate current CCS. [7 kv under load] . ## as is.... with 2.5 A of plate current @ aprx 6900 V under load.... DC input
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pentalab <jim.thomson@...>
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#153
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Re: Can Grid Dissipation in metal GG triodes be increased ????
That's pretty much what Care and Feeding ... ... says. Avg. DC grid- current is measured with an ordinary panel meter.
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R L Measures
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#152
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Re: Can Grid Dissipation in metal GG triodes be increased ????
wrote: with ### whoa. Are you saying RF cathode V x DC grid current = grid diss ???? ### That equates to way below 200 w of grid diss.... based on 45 ohm input Z... and 800w of drive . I can see we
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pentalab <jim.thomson@...>
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#151
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Re: YC-156 amp
wrote: ### 9-12 kw out with 200w of drive. ..easy. [7900 v no load] #### The trbl with 4-1000's is trying to find good one's these days. I had single 4-1000's and pairs of em... between 1976- late
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pentalab <jim.thomson@...>
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#150
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Re: YC-156 amp
That was my reason for moving to 4CX3000A and bought 6 for $100. Jan Erik Holm <sm2ekm@...> wrote: Well they are difficult to get stable. They run just fine now but Ive used 4-1000s for 35 years
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FRANCIS CARCIA <carcia@...>
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#147
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Re: YC-156 amp
Yes understand. Well 4-1000As can be made to run very good, however I just want to try something else. However those tubes they glow very nice in the dark, both filament and plates. 73 SM2EKM
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Jan Erik Holm SM2EKM
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#148
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Re: YC-156 amp
Thanks Tony, OK 19 dB or so, sounds nice. Yes its a nice tube, time to retire the old 4-1000A bottles. As I said it will be a simple swap. I already have two 7.5 V fil transformers in the box, just
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Jan Erik Holm SM2EKM
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#149
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Re: YC-156 amp
Well they are difficult to get stable. They run just fine now but Ive used 4-1000s for 35 years and frankly Im a bit bored with them. 73 Jim SM2EKM ---------------- GGLL wrote:
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Jan Erik Holm SM2EKM
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#146
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Re: YC-156 amp
I have several friends running the YC-156/179 GG, cathode driven with tuned input. With anode voltages of 5500 to 6500 they observe power gains upwards of 19 dB. As you reduce the plate voltage drive
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Tony King - W4ZT <w4zt-060920@...>
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#145
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Re: YC-156 amp
My Buddy still has my 4-1000A with a pair of BC610 plate transformers. It is stable 160 through 10. makes 1500 watts. makes a lot more with 5500 on the plate. "Mike(W5UC) & Kathy(K5MWH)"
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FRANCIS CARCIA <carcia@...>
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#144
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Re: YC-156 amp
Jan Erik Holm escribi: Why?. Best regards Guillermo - LU8EYW.
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GGLL <nagato@...>
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#141
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