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Which is the best 4-1000 2 holer or the GU84B amp
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Harold Mandel
¿ªÔÆÌåÓýOh, wow! ? 3CX1200A7¡¯s, making RF power with no drive. ? Can we squeeze an XT-cut crystal in their somewhere to tune the output frequency? ? ¡¤???????? All I need now is a receiver. Lemme trash the MP. ? Hal ? From:
ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of R L Measures ?
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pentalab
--- In ham_amplifiers@..., "Peter Voelpel" <df3kv@...>
wrote: well and fit in a desktop cabinet.#### since when did anybody start building 8877's that can actually be rebuilt ??? I find that really hard to believe. $1040 US dollars for a 2 x 8877 amp is money wasted imo. A single 8877 for a VHF/uhf project would be a good use for a 8877. ### Yes. Just blow more air into it per my calcs. The YC-243 is just a socketless 3CX-6000A7.. with same air cooling specs. The 3x6 and YC-243 is rated at 6 kw anode diss CCS.... with the following specs..... 204 cfm @ .4" h20 pressure... and an inlet air temp of 50 deg C [121 deg f] . I calculated that by using 310 CFM... the tube would require .9" h20 pressure......... and by using an inlet air temp of 20 deg C [68 deg F].... anode diss would be an easy 9700 w ccs. IF inlet air temp is a little higher... like 25 deg C [77 deg F].... anode diss is still 9200 W ccs. ### The Dayton 5C508 blower will easily provide 320 cfm @ .9" h20 [when run on 1425 rpm high speed.... low speed is 1100 rpm] ### Bottom line is the 3x6 and YC-243 have a 6.125" OD anode cooler.... which is a LOT bigger diam than a 4CX-5000A7 or YC-156 [both are 4.94" OD] In addition... the 3x6 and YC-243[and the 3x3] have a SMALLER diam ceramic stem... way smaller diam compared to the 4CX-5000A7 and YC-156... and also the 4CX-10,000A7's... 3x10's etc. ## With a smaller diam ceramic stem.. AND a big diam cooler.... just increase the air flow by 50%... and simultaneously use a more reasonable 20-25 deg C inlet air temp......... and yes... it's actually 9700 W CCS anode diss. ## When I 1st saw that... "204 cfm @ .4" rating... I knew right there, that this tube [3x6 + YC-243] was a prime candidate for an easy increase in anode diss. The trick is... all the aftermarket chimney's for the 3x6, YC-243 are straight up/down types.... which really restrict airflow... since you can only bore a small ring of holes in chassis.. between grid ring and ID of chimney. Hence the 9.5" square box you see depicted on photo pages. New ones use a taller box.. with a solid teflon top...... no aftermarket chimney required. THEN... u can bore just one ring of BIG diam holes. The trick is the SURFACE area of the holes in chassis should be the same or greater than the underside fin area of the tube in use. You hardly have any underside fin area on a YC-156.... hence the hideous pressures required... just to get 5 kw anode diss. ### Check the airflow specs on tubes like the YC-156.... they require huge amounts of pressure. Look at a 3x 10 vs a 3x 15. Both have the same 7.05" diam cooler.... same weight, etc.... they just blow more air on a 3 x 15. You blow the same amount of air on a 3x10.... and u now have turned the 3x10 into a 3x15. ### Using the above improved cooling scheme, the air temp out of a 3x6 is barely warm with 13 kw PEP out on ssb. Let the VOX drop out.... run 30' over to amp as fast as you can, and you will have COLD air coming out of the 3x6 / YC-243 !!! ### Svetlana does NOT make a YC-243... only Eimac... and Only available from Arnold Howell Of Howell Tube sales... since it is his design. Svetlana does NOT make a socketless 3x6. Svetlana does make a 3CX-3000F7... same as Eimac. [ F7 version has 3 x flex leads] The YC-243 is going to be around $1100 - $1200 US funds... and IS rebuildable. Later........ Jim VE7RF [mailto:ham_amplifiers@...] On Behalf Of pentalab |
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pentalab
--- In ham_amplifiers@..., "hbmandel" <ka1xo@...> wrote:
### I ran my last 4-1000 with just 4400 V under load of 600Ma.Additionally, the 4-1000A, with a 6KV at 1 Ampanode requirement needs a power supply to suit, and [4800 v no load]. ### With 120 w of drive from a Drake T4XC... it would produce 1950 w output. ### The last batch of new surplus lytics I bought were $10.00 each..... 2500 UF @ 450 v The ones u see ont he photo page are a combo of 3700 UF @ 350 V [3" x 6"] and 5200 UF @ 350 V [3" x 9"] ### These new 2500 UF @ 450 V lytics I bought are tiny things... 2" diam x 4" long.... rated at a whopping 9.7 A CCS ripple current [120 hz] . Use V squared x uf and then divide by 2,000,000 to calculate joules. Globs of energy storage from a string of these new wonder caps.... = zip for ripple + superb dynamic regulation. Later.... Jim VE7RF
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On Jan 18, 2007, at 12:38 PM, Harold Mandel wrote:
Probably not since g-g stages usually oscillate above the grid resonance, R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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FRANCIS CARCIA
Hey Toll_Free, Ham radio needs guys like you. You don't have to learn code anymore?and I'm sure you could study and pass the extra test. If you can lift your leg why not pee with the big dogs. 11 meters is broken most of the time come down lower and have a ball. I'm an AMer so have 2 strikes against me. gfz 1800 Toll Free wrote: On Thu, 18 Jan 2007 04:22:37 -0800, R L Measures wrote: |
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Wow.
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I happen to have my Tech ticket. The day I went in and got my tech I passed novice through written. That was 12 or so years ago. I've tried learning code, but ended up having to play the way I have. And believe you me, I am READY to go forward when February rolls around :) My TS-440SAT will be retired in trade for a 940S I believe...... Seems like the best used radio on the market at the time, if I get a nice late model. Anywho.... Thanks for the invite, and if I find ya, I'll holler :) lol --Toll_Free On Fri, 19 Jan 2007 12:28:08 -0800, FRANCIS CARCIA <carcia@...> wrote:
Hey Toll_Free, --
*Ratings are for transistors, tubes have guidelines* |
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On Jan 18, 2007, at 8:57 AM, 1800 Toll Free wrote:
On Thu, 18 Jan 2007 04:22:37 -0800, R L Measures <r@...> wrote:chortle Except that with a tetrode-with-handles, where input-Q matters mot, a continuous-coverage roller-coil tuned, grid circuit is do-able. It has tons more gain.Good point. The original "Plywood Box" 8170 amp cost c. 9.5? per watt, thanks to parts donations from my friends. Especially when you figure in the2x to 4x the feedback-C is a good thing . . . . . if you need an oscillator. As someone else had7kW out / 11.6kW in with a of a pair of 8877s is walking on thin ice. Good news. The 8170 project was the d¨¦nouement of my amp-education. After I got everything figured out and working, I was determined to pass along what I learned to other Hams who enjoyed building and did not enjoy being QRMed. As I understand it, the Fuehrer of AMPS himself, W8JI, was building an 8171. Didn't do plywood, but... Also have a pretty kick assThe SB-220 can never be kick-ass anything, but it makes a decent driver for the 20-out 8160. Without a major mod, the Plywood Box will not do 11m/10m. Bought a house instead.Why ? I was the first Ham on the West Coast to admit to running a tetrode with handles, and the only people who got upset and wrote letters to the FCC were contesters who ran tetrodes with handles and claimed to be absolutely, positively, 100% legal. ur welcome, Mr. _______ ? R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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pentalab
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
### which is exactly why u stick in one suppressor.... PER TUBE !2x to 4x the feedback-C is a good thing . . . . . if you need an AMPScheers, Mr. __"X"____?not enjoy being QRMed. As I understand it, the Fuehrer of himself, W8JI, was building an 8171.### well he does have a 160-10m YC-156 on his website. He claims it's a... "medical amplifier". At least the rest of us aren't BS'ers'. 10 kw out cw can make that 160m array of his really honk. ### real major mod. I have a call, but since I flaunt > 11 meter high poweroperation, it behooves me to keep it under wraps. a tetrode with handles, and the only people who got upset and wrote letters to the FCC were contesters who ran tetrodes with handles and claimed to be absolutely, positively, 100% legal. ### well, I guess that makes the contester's... "hypocrites". I was told back in the late 70's.. early 1980... that an ex prez of the ARRL... some fellow from W0 land... used to run 10 kw in the 60's. AES tells me they sell 10 kw slugs like popcorn...... so somebody's.. "boilin oil" ### BTW... NONE of my tubes have handles. I supose if one is creative.... you could always hacksaw off the handles... and retweak the paint job on the side of the tube. Sorta like the world's biggest 3CX-1000A7. Later... Jim VE7RF ur welcome, Mr. __"X"_____ ? |
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On Jan 20, 2007, at 5:27 AM, pentalab wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:Using the same wattage R-supp, two single-R-supp VHF suppressors in series provide superior cooling to R-supp than than a single VHF suppressor using two R-supps in parallel.### which is exactly why u stick in one suppressor.... PER TUBE !2x to 4x the feedback-C is a good thing . . . . . if you need an ** Indeed. However, if Tom built an 8171 amp that delivers 15 - 18, I doubt he would say anything about it publicly.### well he does have a 160-10m YC-156 on his website. He claimshimself, W8JI, was building an 8171.cheers, Mr. __"X"____?not enjoy being QRMed. As I understand it, the Fuehrer of AMPS ** 20m - 10m, trifilar 1:9 grid xfmr; #10awg grid roller-L; add 3/4" Cu tubing, 0.7uH tank-L; three GH-1s in parallel for T/R switching. However, when 10m isn't open, a 20db amp is a dead fish.### real major mod. ** -- or heating lots of air.I have a call, but since I flaunt > 11 meter high poweroperation, it behooves me to keep it under wraps.a tetrode with handles, and the only people who got upset and ...cheerz, Jim. R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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Robert B. Bonner
For the 8877 slammers, the 8877 is just fine. There are bunch of limits one
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should watch. Filament Voltage, Maximum Plate Current, Maximum Grid Dissipation (which can only be monitored via reading grid current and guessing) and plate dissipation. (Which needs to be calculated) The 8877 is one of the first tubes for ham radio that actually when ran at its maximum ratings maxed out everywhere. 4KV at 1A made 4KW input which makes around 2500W output and dissipates close to 1500 in the anode. All ran within the tubes maximum ratings. Where tubes like a 3-1000Z can safely be ran over their maximum anode current in ham service (I've ran upwards of 1.4AMPS) without breaking their cathode or melting the plate, the 8877 user won't be so lucky hammering on his tube's cathode. In my 77DD prototype the owner got 12 years of use out of a pair of 8877's in regular contest service and daily use while being run conservatively. For some reason its always the AMATEUR WAY to run things way the heck up there instead of cruising. Oh we say the ALPHA SX loafs at 1500 watts, but I bet NOBODY HAS EVER RAN ONE AT 1500W. An SX is a very poor amplifier for an 8877. (The filament is all over, and they tell you to run the grid at too high a mA, Plate supply all over the place) My recommendation is to monitor filament voltage. Keep the Grid Current around 50mA with an ABSOLUTE MAXIMUM for short exposure of 100mA. On my current amplifier the grid trip is set at 100mA and the green arc ends at 50mA. I start paying close attention passing .900mA of plate current, but do take it to 1A. I have an adjustable blower, if the exhaust air smells hot, I turn up the blower. Meaning if I'm just doing fast break SSB rag chewing it can be ran moderate, but hammer down long winded rag chewing or contest type operating the blower needs to spin up more. The cooler you run one of them the happier it is, balance between shack quiet and a cool tube. You can never blow enough air through a tube. Where a glass tube will show you the error of your ways, a ceramic tube has already been damaged with a black anode if you do something stupid to it. So if you follow the rules with an 8877 a pair will make right at 5000W nicely. Oh they will do more, but then you are pushing the ANODE DISSIPATION limit which is very unwise. The 8877 was tested for pulse service before they built the 3CPX version and was ran to 8KV. I have successfully ran 8877's to 5KV on a regular basis. It does allow you to reach the "ANODE DISSIPATION LIMIT" below the maximum anode current limit. You have no need to be afraid of the tube. However if you are somewhat amplifier non-savvy or ham fisted, go with a different tube selection like a 3CX1200A7. If you've got a problem flipping to a carrier with the drive all the way up, it¡¯s a matter of time before your prized bottle leaves the amplifier. (no matter what tube you are using) Most of the lurkers here pay attention to what's getting said without posting. Most of them will NEVER build their own amps, but are curious regarding what the "experienced guys" are up to. For sure most will never build an amp with a tube with handles. It takes considerably more experience to keep 6KV tidy than it does 3KV. SO this constant recommendation from some that such and such tube with handles are so much a better value than an 8877 or other tube is HOOWIE for the guy who hasn¡¯t built say 10 amps in his past. I'm sure if I last long enough where senility sets in hard, I'll run a "truck" tube instead. The 8877 is a finesse type device. And I own a pile of amps running them. BOB DD -----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of R L Measures Sent: Saturday, January 20, 2007 6:43 AM To: ham_amplifiers@... Subject: Re: [ham_amplifiers] Which is the best 4-1000 2 holer or the GU84B amp On Jan 18, 2007, at 8:57 AM, 1800 Toll Free wrote: On Thu, 18 Jan 2007 04:22:37 -0800, R L Measures <r@...> wrote:chortle Except that with a tetrode-with-handles, where input-Q matters mot, a continuous-coverage roller-coil tuned, grid circuit is do-able. It has tons more gain.Good point. The original "Plywood Box" 8170 amp cost c. 9.5? per watt, thanks to parts donations from my friends. Especially when you figure in the2x to 4x the feedback-C is a good thing . . . . . if you need an oscillator. As someone else had7kW out / 11.6kW in with a of a pair of 8877s is walking on thin ice. Good news. The 8170 project was the d¨¦nouement of my amp-education. After I got everything figured out and working, I was determined to pass along what I learned to other Hams who enjoyed building and did not enjoy being QRMed. As I understand it, the Fuehrer of AMPS himself, W8JI, was building an 8171. Didn't do plywood, but... Also have a pretty kick assThe SB-220 can never be kick-ass anything, but it makes a decent driver for the 20-out 8160. Without a major mod, the Plywood Box will not do 11m/10m. Bought a house instead.Why ? I was the first Ham on the West Coast to admit to running a tetrode with handles, and the only people who got upset and wrote letters to the FCC were contesters who ran tetrodes with handles and claimed to be absolutely, positively, 100% legal. ur welcome, Mr. _______ ? R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org Yahoo! Groups Links |
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Mike Sawyer
BB said: "Most of the lurkers here pay attention to what's getting said
without posting. Most of them will NEVER build their own amps, but are curious regarding what the "experienced guys" are up to. For sure most will never build an amp with a tube with handles. It takes considerably more experience to keep 6KV tidy than it does 3KV." Yep, you're talking about me there, Bob. I do have a home brew pair of 813's on a chasis that belonged to my friend/elmer, Eric, WB4VVI (SK). His son went into an LSD induced stupor and damn near destroyed it. I have resurrected it but need to put the finishing touches so it may "push the ether' again. I'm not a co(r)ntester nor do I chase DX. The only amp I have that is operable is a venerable and near indestructable RCA SB-1K maritime amp. A pair of 4-300Z's @ 2800 VDC will do 1K all day long or as VE7RF says, "### 1K full crx." I am envious and would love to build a "heavy box" but I don't have the need or the ego to do so. YMMV. Mod-U-Lator, Mike(y) W3SLK |
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On Jan 20, 2007, at 8:27 AM, Mike Sawyer wrote:
Rich said: "** Indeed. However, if Tom built an 8171 amp that delivers 15 -True, Mike, but there's the our little secret tooting to drinkin' buds and public tooting. OTOH, the project could well be on hold until he completes a class in alternating-current circuit-analysis. cheerz, . R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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craxd
--- In ham_amplifiers@..., R L Measures <r@...> wrote:
the AMPS listTrue, Mike, but there's the our little secret tooting to drinkin' One can build anything, but making it work correctly is another problem. I seen the photos, and I highly doubt that was for a piece of medical equipment as rough as it looked. He'd be lucky to sell it to a RF heating manufacturer. Most of those manufacturers, especially medical, build their own in house. When you see one, they're totally profesional in appearance, and constructed to the upmost quality. I've not seen a piece of medical equipment that uses rack mount construction since the 70's. Most everything like that is installed in custom cabinets with doors. These manufacturers have CNC brakes and turret punches, plus big paint lines. It's hard to do this by hand using hand punches and hole saws. Best, Will |
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Robert B. Bonner
Yeah Mike it does take an EGO defect of some kind to build the heavy iron.
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But what the heck, by the time my next life comes around there probably wont be ham radio to do it again. So we have to do it now. BOB DD -----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of Mike Sawyer Sent: Saturday, January 20, 2007 11:46 AM To: ham_amplifiers@... Subject: Re: [ham_amplifiers] Which is the best 4-1000 2 holer or the GU84B amp BB said: "Most of the lurkers here pay attention to what's getting said without posting. Most of them will NEVER build their own amps, but are curious regarding what the "experienced guys" are up to. For sure most will never build an amp with a tube with handles. It takes considerably more experience to keep 6KV tidy than it does 3KV." Yep, you're talking about me there, Bob. I do have a home brew pair of 813's on a chasis that belonged to my friend/elmer, Eric, WB4VVI (SK). His son went into an LSD induced stupor and damn near destroyed it. I have resurrected it but need to put the finishing touches so it may "push the ether' again. I'm not a co(r)ntester nor do I chase DX. The only amp I have that is operable is a venerable and near indestructable RCA SB-1K maritime amp. A pair of 4-300Z's @ 2800 VDC will do 1K all day long or as VE7RF says, "### 1K full crx." I am envious and would love to build a "heavy box" but I don't have the need or the ego to do so. YMMV. Mod-U-Lator, Mike(y) W3SLK Yahoo! Groups Links |
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On Jan 20, 2007, at 12:03 PM, craxd wrote:
--- In ham_amplifiers@..., R L Measures <r@...> wrote:As I found out with the 8170 project.the I cut the big holes for the 8170 project with a Sears and Roebuck coping saw I got for Christmas when I was 6-yrs old. The blade was a 32-teeth/inch for sheet-metal cutting. R. L. Measures, AG6K, 805.386.3734Best, r@..., rlm@..., www.somis.org |
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Randy
¿ªÔÆÌåÓýRobert B. Bonner wrote:Sorry if I'm dragging things too far OT, but, speaking of HV and keeping things tidy, I'm wondering what knowledgeable folks think about X-ray exposure... i.e. at what voltage range do things start to get interesting? I once saw someone comment on a homebrew amp that was for sale, running ~5kV as I recall, and the poster seemed quite alarmed. Obviously, the B+ is the biggest concern, but, then again, there's instant notification when you screw up THERE (some say that Jesus lives in the B+ supply, and you can meet him there). Thanks for any input. 73, Randy KZ4RV .. |
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I've always prayed that I'm correct in assuming I'm safe from X and other "bad" rays staying below 12Kv anode voltage.
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It seems somewhere, back "then", I read that the tubes we commonly use (ie, up to the 15Kw diss level) they really didn't start producing a measurable amount of bad things until you hit >10Kv and more like >12kv. If I'm wrong, I'll be sterile soon... But, I got 3 boys, so I'm ok... Fire up that variac! --Toll_Free On Sat, 20 Jan 2007 16:06:24 -0800, Randy <fu.bar@...> wrote:
Robert B. Bonner wrote: --
*Ratings are for transistors, tubes have guidelines* |
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I've looked upon it as the Grim Reaper....
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--Toll_Free On Sat, 20 Jan 2007 16:06:24 -0800, Randy <fu.bar@...> wrote:
Robert B. Bonner wrote: --
*Ratings are for transistors, tubes have guidelines* |
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On Jan 20, 2007, at 4:06 PM, Randy wrote:
Robert B. Bonner wrote:Randy == As I understand it, soft x-rays begin to happen c. 12kV.Sorry if I'm dragging things too far OT, but, speaking of HV and keeping things ... R. L. Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org |
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