Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- Ham-Amplifiers
- Messages
Search
|
Re: Straightening out AMPS.... Doc Bob kicks some ass.
On Fri, 12 Jan 2007 17:23:18 -0800, pentalab <jim.thomson@...> wrote:
--- In ham_amplifiers@..., "Robert B. Bonner"Pill: MRF455 looks like a small pill of aspirin. 192 devices are built as 3 64 device amplifiers, and then they combine them.
Using a non linear amplifier produces distortion, unless your high level modulating it. Although it is common to run class b/c (whichever you choose to call it) grounded base when running high Vcc. This mode does create a LOT more junk on the band..... Another 'trick' if you will the competition guys do is overdrive the living hell out of their amps. Swinging wildly as a switch, they can get quite a bit more output.... But C'mon, how clean is it, and how much MORE real output power is it, when you're driving a 2879 with 80 watts PEP, and running it at 23 volts? Sure, it's making the Bird move wildly to the right (if you have a peak kit), but.... They don't really rate the distortion output of these amps. Most "builders" (they don't call themselves tech's anymore, becauses too many of the real tech's out there put them in their place and showed them they can't design or fix themselves out of a wet paper box... Most of the "builders" on 11 meters actually came from club DaveMade, and through bad drug deals, branched out on their own.) just copy DaveMade's design, and that's nothing more than a different mix of ferrite and Motorola App Notes clobbered together on a board that's dremel tooled to etch it... Or, more often than that, they just hot glue small strips of pc board material. These amps work, and work quite well at what they are designed to do, but to ask about SSB use is ludicrous. since the cxr power is only gonna be 1/5 of the pep output. You No, actually they rate their stuff at full bore, carrier power. I actually watched a box I helped build get tuned up. They turn the carrier control up on the radio, and tune every stage for max suds. Just make the meter move farther to the right, and that's alright. Of course, since the waveform is nothing more than a squarewave when it hits the pair of 4CX15000's, they can take being driven by 15,000 watts. The duty cycle is a lot less than 100 percent, overall. It's a 10 second key, usually. It's RF Drag Racing. Two guys line up in a field, and they have a guy standing up in the middle. He raises his hands, you hit your motor and fire down.... When he drops his hands, it's all over.... It is taped at the "watergate" station, and run in a typical elimination manner. Each time, a winner is brought up, usually over the air. That night, the watergate (tape) is played for all to hear at the keydown.
You would be amazed at how much money is flashed around. It breaks down as such. 1. Some of it is drug money. It IS a predominately black sport, but honestly, I find more drug infested riff raff on the white end of the racial scale. However, honestly, not much of it is drug based, and most of that comes from back east, mostly northeastern. 2. Mostly it's successful business owners. The person that I learned to work on large amps from (he used a 4CX10,000 in 1986) owned a roofing company. The mobile I spoke of earlier is owned by a trucking company owner. One of the builders of these large amps owns a construction company, and he gets the hotrod motors from his brother who is a NHRA drag racer. So, it isn't a bunch of lames. One of the guys who is building biased, class AB boxes is a famous entertainer.... 5 years ago, he was building non-biased grounded base crap, but over the last 5 years discovered the proper 4/1 carrier pep relationship beats raw needleswing.
No problem. I had / have videos of these guys in action. That dual 10,000 box spoken up above actually destroyed the AC power adapter on a camcorder when we where taping it. People talk of contesters having severe RF...... The biggest station on I know of on 11 meters right now is running.... Well, he has a 50Kw slug in his line section, and it can move pretty much as far to the right as he wants it to. That is fed into an 89 foot long 9 element longboom yagi. His protoge on the opposite side of the US has a 90 foot beam with over 35 thousand watts of plate dissipation on his final.... Dedicated 400A 3 phase input. 11 meter shootouts, now THAT'S extreme contesting. Have fun. --Toll_Free (I have a few pictures of some of these beasts, a dual 15,000 box in various stages of assembly. The 3CX3000 is now the driver of choice on 11 meters... Those are feeding our single 20,000 boxes. Contesting has no limits, when people aren't risking their license. I think it's gotten way out of hand, but hey, thats the way the needle swings, right?)
-- *Ratings are for transistors, tubes have guidelines* |
|
Re: Straightening out AMPS.... Doc Bob kicks some ass.
Robert B. Bonner
Yeah I seriously thought of getting into that game myself at one time.
toggle quoted message
Show quoted text
What a way to make a living. I was going to take a suburban and remove the 454 and place a diesel 480v 3ph generation unit in it under the hood and back into the cockpit. Use a 100HP electric motor to move the BURBAN and fill the rest of the back with big tube power. Wear a lead lined space suit and go for the gusto. But then I got a huge dose of reality and that was that. It felt good to know I had a plan. BOB DD -----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of pentalab Sent: Friday, January 12, 2007 7:23 PM To: ham_amplifiers@... Subject: [ham_amplifiers] Re: Straightening out AMPS.... Doc Bob kicks some ass. --- In ham_amplifiers@..., "Robert B. Bonner" <rbonner@...> wrote: ### anybody who doesn't know what a 3x3 is... well... they should go straight to their ARRL hand book.... where they still won't figure it out. ### Dunno where the 11m term "pill" came from. Saw that a few yrs back.... "192 pill amp" ... what did they do.... build a heatsink the size of a 4 x 8 sheet of plywood.... and then run the entire mess on 18V ?? What's the IMD on ssb, on these things ?? ### Using a linear amplier on AM seems kind of silly to me..... since the cxr power is only gonna be 1/5 of the pep output. You woulod have to pulse tune it to full pep output [tube amp].... then, with an unmodulated cxr... adj the cxr for 1/4 to 1/5 the pep output. ### what exactly goes on in one of these shoot outs ?? I heard each vehicle has an assigend freq... and they each send a 10 sec dead cxr..... with the referee 20 miles away... and his spectrum A. ## I also heard some times there is as much as $25 K in prize money. Who's bank rolling all this prize money ...Eimac ? Later.... Jim VE7RF
Yahoo! Groups Links |
|
Re: Straightening out AMPS.... Doc Bob kicks some ass.
pentalab
--- In ham_amplifiers@..., "Robert B. Bonner"
<rbonner@...> wrote: ### anybody who doesn't know what a 3x3 is... well... they should go straight to their ARRL hand book.... where they still won't figure it out. ### Dunno where the 11m term "pill" came from. Saw that a few yrs back.... "192 pill amp" ... what did they do.... build a heatsink the size of a 4 x 8 sheet of plywood.... and then run the entire mess on 18V ?? What's the IMD on ssb, on these things ?? ### Using a linear amplier on AM seems kind of silly to me..... since the cxr power is only gonna be 1/5 of the pep output. You woulod have to pulse tune it to full pep output [tube amp].... then, with an unmodulated cxr... adj the cxr for 1/4 to 1/5 the pep output. ### what exactly goes on in one of these shoot outs ?? I heard each vehicle has an assigend freq... and they each send a 10 sec dead cxr..... with the referee 20 miles away... and his spectrum A. ## I also heard some times there is as much as $25 K in prize money. Who's bank rolling all this prize money ...Eimac ? Later.... Jim VE7RF
|
|
Re: hi power mobile
Robert B. Bonner
Typ metric to queens english and vice versa faux pas. Don't
laugh.... a few commercial airliners went down cuz of a litre to US gal screw up. I have seen several containers made in the US.. where they will state the eq metric as anything from 3.8 L... to 3.82 L.... all the way up to 4.0 l. later... Jim VE7RF The hardest thing I EVER DID AS A PILOT wasn't flying through a thunderstorm, it was gassing up our Aircraft in CANADA-EH? I was a First Officer at the time and flew into Toronto in a FedEX Fokker F-27 and needed POUNDS of Fuel. Pounds then converted to gallons, converted to LITERS to tell the fuelers so they could load us up. I triple checked the calculations and when done had to make sure it was really as full as I wanted it. Airplanes fly by pounds not liters. Pounds of people, pounds of cargo, pounds of fuel, pounds of money. Oh that last one might be piles of money. How dare they sell gas by the liter? OK that covers VOLUME. Lets talk about distance. The only thing I understand in millimeters is the length of my wife's cigarettes and a cigar ring gauge. You foreigners speak English or get the hell out, hahahahaha OH, you are already? HUM? I was working on a NEW measurement system and insist it be implemented to replace both the ENGLISH and Metric systems. In my system all time, speed and distance measurements are keyed off the SPEED of light in a vacuum. When you broke it down to a millionth or whatever the METER is slightly off and so is the yard. Think about the logic. This is actually a universal measurement... As far as a standard volume measurement that became more difficult I went back to how much I could WIZZ at 12AM on a night out at the bar after a 6 pack @ 59 degrees and 29.92 barometric pressure as a SCHMEDLAP. This will replace the gallon and liter... Until a better system can be thought up, you're stuck with that.. SO I expect the world to start using SCHMEDLAPS PER LIGHTYEAR AND THINGS LIKE THAT. BOB DD |
|
Re: hi power mobile
pentalab
--- In ham_amplifiers@..., "Peter Voelpel" <df3kv@...>
wrote: 40cm DIAMETER on 80m. ### say what ?? 1 cm= 10mm 40cm= 400mm = 16" diam.. which is huge. ### IF u meant 40mm... that's only 1.6" Coils sized from 25-40cm diameter were close in competition, justthe width of the S-meter needle in difference. #### 25-40 mm = 1" to 1.6" ### 25 cm to 40 cm = 10" to 16" #### 5" = 125mm.... or 12.5 cm. Typ metric to queens english and vice versa faux pas. Don't laugh.... a few commercial airliners went down cuz of a litre to US gal screw up. I have seen several containers made in the US.. where they will state the eq metric as anything from 3.8 L... to 3.82 L.... all the way up to 4.0 l. later... Jim VE7RF 73 |
|
Re: Straightening out AMPS
Tony King - W4ZT
That was a GREAT piece of work Bob!
toggle quoted message
Show quoted text
Too bad there so many that can't or wont buy into the simple things that make us smile. Q signals belong on CW... that's why they were invented ;) Roger isn't a question, except on 11 meters! Neither is QSL, except on CW. Best regards... not best regardses (73's) LOL! Tony W4ZT Robert B. Bonner wrote: Yeah we had to straighten out a few of the guys on AMPS today. |
|
Re: Straightening out AMPS
Phil Clements
--- In ham_amplifiers@..., "Robert B. Bonner" <rbonner@...>
wrote: Verily, verily! they have eliminated all of the code, most of the theory, and now they are going after our "jive-talk!" I guess the "Q" signals will have to go next, and then they will hire hit men to finish us off. (((73))) Phil Clements, K5PC |
|
Re: hi power mobile
pentalab
--- In ham_amplifiers@..., "Peter Voelpel" <df3kv@...>
wrote: coils, 500W are all one needs to work any station heard on 80m and breakmost dx pileups easily.#### I find this hard to believe. And 5" diam coil is pretty damn big.... like 125mm. Ur 80m mobile ant is still -9 db.... most 80m mobile stations and 500 w is bare minimum... not exactly pile up busting material. Jim VE7RF |
|
Dentron Amp Chassis Plating
Anyone happen to know what was used to plate the chassis in Detron
amps? I have one that has some rust at the seam on the front(behind the aluminum front panel) and thought I would clean it up and seal it before it spread, but I didn't want to use something that might damage the unaffected plating. Thank you, Anthony, NT4X |
|
(No subject)
Not all alternators are capable of charging 16-18 Volts. The factors that determine an alternators output are stator windings, stator/rotor spacing, rotor current and number of poles, and RPM.
?
There are cheap, loosely coupled, small winding alternators that can barely achieve 1.2V above battery volts (under load), even with full battery volts applied to the rotor.
?
-John, N9RF
?
?
?
On Thu, 11 Jan 2007 08:18:54 -0800, PA3DUV <pa3duv@...> wrote:
> That's an interstuing approch, thanks. I was not aware of the fact that? > a 12 > V (or 14.4 Volt) alternator would supply 16 or even 18 VDC when connect? > to a > 16 or 18 V battery stack. . Most comprehensive set of free safety and security tools, free access to millions of high-quality videos from across the web, free AOL Mail and more. |
|
Re: Gu84b anode voltage
Harold Mandel
开云体育Dear Jan, ? I am currently building a GU-84b Grid-Driven Tetrode amplifier and my Anode Transformer is 3.0KV at 2 amps, and the output from the rectifiers and filters are 4,242.0 Volts, D.C. ? When designing the amplifier and anticipating a certain Anode Voltage, the Grid and Screen are affected, as is the anticipated output impedance of the tube, which in turn affects the tank-Q and the components making up the tank circuit. ? So feel free to crank 4KV, Jan. It’s been done before, and the GU-84b, as long as it’s cooled appropriately and is presented the right impedances, will serve well. ? Please also remember to carefully monitor the filament voltage, as a few hundredths high will severely age the tube! ? Hal Mandel W4HBM ? From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of on6zg
Sent: Thursday, January 11, 2007 5:17 AM To: ham_amplifiers@... Subject: [ham_amplifiers] Gu84b anode voltage ? Hi, |
|
Re: Mobile power supplies revisited
On Thu, 11 Jan 2007 08:18:54 -0800, PA3DUV <pa3duv@...> wrote:
That's an interstuing approch, thanks. I was not aware of the fact that It only works because for the "sense" lead to see the "14.4" volts it needs to, the alternator has to put out 18 volts... It has to make up that 4 volt pad... It's the location of the sense lead and automotive electronics that make this method work.
I'd go with the method your looking at, or another one we did in the keydown circuit was a 12 volt and an 6 volt battery. Works just like before, just more Vcc.
If you do the 18 volt stack, using 12 and 6 volt batteries, you could pull from the 12 volt side, use a steering diode (large current, stud mount) to charge another 12 volt battery just for the car electric system. That would give you isolation, and a psuedo dedicated circuit for your amp as well. --Toll_Free |
|
Re: Mobile power supplies revisited
PA3DUV
That's an interstuing approch, thanks. I was not aware of the fact that a 12 V (or 14.4 Volt) alternator would supply 16 or even 18 VDC when connect to a 16 or 18 V battery stack.
toggle quoted message
Show quoted text
In mmy case battery capacity is no issue, there is plenty of space to even fit 8 two volt cells. The point is the absolute lack of space for a second or larger frame alternator. On second thought is might be an option to use an 18 V battery stack (with the stock alternator connected to the +18 VDC of the stack) and use a 18 => 12 V DC DC 30 amp converter to supply the needed charging current to the starter battery and the car electrical system. Cheers, Dick PA3DUV ----- Original Message -----
From: "1800 Toll Free" <TollFree1800@...> To: <ham_amplifiers@...> Sent: Thursday, January 11, 2007 1:05 AM Subject: [ham_amplifiers] Mobile power supplies revisited Here's another thought, more geared towards the gentleman in .eu who was |
|
Re: hi power mobile
PA3DUV
开云体育Peter,
?
3 dB is what we've measured using S-meters from an
Icom 756ProIII, so for what it's worth. Coupling from the vertical also occurs
with the 5 inch loading coil, I can see if cars are passing on the other lane by
looking at the VSWR. Even lightpoles, traffic signs etc result in detuning. This
sometimes results in a fast flutter, as reported by fixed stations during mobile
QSO's on 80 meter.
?
On next occasion I will do a temperature
measurement on?a centerloaded vertical with a 3" and 5" loading coil, in
order to get a better?impression of the dissipated RF in the coil. But,
without doubt there is a significant difference in antenna performance when
the?loading coil goes from 1.7 inch to 5". The difference between a High
Sierra HS1500, featuring a 1.7 inch diameter loading coil and a HiQ 5-80 with a
5 inch loading coil was 10 dB on 3600 kHz.?I rember?the loading coil
on the 1.7 inch antenna ran hot to the touch and the contactor almost burned
out.
?
Cheers, Dick
PA3DUV
?
?
?
?
?
|
|
Re: hi power mobile
Peter Voelpel
Hi Dick,
That is very unlikely at same wire size. 3db difference would mean half of the transmitting power being lost across the coil. The ARRL program "mobile" calculates 1,3db difference. But you are right, the larger coils give no remarkable improvement, but make it much easier with tabs for band change. The disadvantage is the detuning while passing trucks. 73 Peter ________________________________ From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of PA3DUV I found approx. 3 dB difference between a 3 and 5 inch loading coil in on air test on 80 meter. Anything larger than 5 inch the difference was neglectible. |
|
Re: hi power mobile
PA3DUV
开云体育Peter,
?
I found approx. 3 dB difference between a 3 and 5
inch loading coil in on air test on 80 meter. Anything larger than 5 inch the
difference was neglectible.
?
Cheers, Dick
PA3DUV
?
?
?
?
?
|
|
Re: hi power mobile
PA3DUV
开云体育I could not agree more Greg.
If multibanding is required there is always a
compromise. Also remote control is an issue here, this morning when I was
tooling down the highway in drizzling rain?alI had to do was run the
contactor down by pressing a switch in order to check out 3780-3800 kHz. The 10
kHz bandwidth of a short centerloaded vertical makes remote control a no
brainer.
My experience on 160, 80 and 40 from the mobile is
that hearing is much easier than being heard. @ -8.5dB antenna gain the 1 kW
input makes a mobile signal equal to the barefoot crew.?
?
Cheers, Dick
PA3DUV
?
|
|
Re: hi power mobile
Robert B. Bonner
The highest performance antenna I have ever had was the Texas BUGCATCHER.
toggle quoted message
Show quoted text
Sort of like Peter's. That antenna could get as tall as I wanted and I carried a bundle of parts to do whatever I felt like at the time. 10-12-15-17 used NO COILS, they were combos of masts and Steel CB whips, (fullsized) I used about 1-3 turns on 20 meters of the 40 meter bug coil and about half of it on 40. That setup was UNBELIEVABLE FOR DXING ON 40. HOWEVER, convenience finally took over and I mounted up the Predator Screwdriver. I then used many of my BUG masts, whip parts and top hat to super dooper the PRED and closed the gap some between them. All my BUG friends have since changed over now for the ability to be rolling and changing bands. With these high performance antennas like the Predator, you don't give up much in performance after you do some of that good BUGCATCHER radio stuff to it. Then crank up the amp. For anybody who thinks Hamsticks or Hustlers are mobile antennas shame on them. BOB DD -----Original Message-----
From: ham_amplifiers@... [mailto:ham_amplifiers@...] On Behalf Of badgerscreek Sent: Thursday, January 11, 2007 6:04 AM To: ham_amplifiers@... Subject: [ham_amplifiers] Re: hi power mobile For a 5 base and a 6ft whip. The base being 1 inch and the top being a 1/4 inch in diameter, i calculated that the optimum coil diameter is 7.5 inches. This is for 10 Gauge Wire. I used the Mobile.exe program from the ARRL antenna handbook. This is for a frequency of 3.5 mhz. I always wondered how the screwdriver makers can make the claim that bigger coils are always better especially when you want to cover from 3.5 to 30 mhz. For best efficiency when i did an exhaustive analysis using many antenna lengths, i found that you need two different coil diameters for the high and low fequency ranges for maximum efficiency. You still cant beat a monoband coil with a tophat. However the differences are fractions of a S unit so it might be a moot point. Its far easier getting gain from the amplifier in the mobile once you close to optimum efficiency in the antenna department. Greg --- In ham_amplifiers@..., PA3DUV <pa3duv@...> wrote: for a multiband centerloaded vertical with 3500 kilocycles as the lowest frequency. coils, 500W are all one needs to work any station heard on 80m and breakmost dx pileups easily.[mailto:ham_amplifiers@...] On Behalf Of 1800 Toll Freeyou just need to do a little bit of lookin around before you spend the hardearned dollars :) Yahoo! Groups Links |
to navigate to use esc to dismiss