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Tube amplifier
- Thread starter fritzoreo
- Start date
When I had the EndFeed up I was going for Work All Toasters but got the Worked all Baby Monitors.
I was getting ready to put some major power in to the air when one of my neighbors came up just when hit the power,
So now I have worked all Pace maker/defibrillators.
(Just Kidding)
So now I have worked all Pace maker/defibrillators.
(Just Kidding)
I think the biggest drawbacks when using a true amateur radio amplifier on 11 a.m. is if your not using a (Mars) modified HF, or a 50+ watt modified export you're going to need a separate driver, and a foot switch. I myself have never owned a export radio. I would love to purchase a brand new ameritron for use with my sonar, and Madison. but the thought of having to use another amplifier in order to drive it, and a foot pedal kills the thought of purchasing one. It's so much simpler to use what's Been built for 11 use. And we all know what those are. Palomar, Galaxy, pal, d&a, kenrich, black cat, Texas star, and the list goes on. It's the only reason why I don't own and ameritron. I would love nothing more than to run a brand new or near new well-built, well-designed amplifier on 11. But those two issues I mentioned above stop me dead in my tracks from doing so. My disability kills the footswitch idea, and I have never even considered using one amplifier in order to drive another (unless the big amp was a 10 k+lol). Both my transceivers are set at 1 1/2 Watts, and amplifiers made for CB radios are simply the easiest way for me, and I believe most chicken banders to go. If a chicken bandder doesn't mind the footswitch, and having to drive a big amp with a smaller one then go for it. As far as splatter goes I have never gotten a single complained weather 10 channels away or a single one. No neighborly RFI, but I do understand that doesn't mean these amplifier run clean. Anyone with a modern HF that has a built-in scope probably knows exactly when I'm on the air from five (or more) channels away even though I'm not splashing them. I do believe that's the way those Scopes work. I could be wrong. If so please take me to school on that. I only mention that because a local with a 7300 once told me he knew I was on 38 LSB when he was a few above 40. I asked him if I was splashing him? His answer was no. He explained to me that he just knew I was on the air by looking at his scop/waterfall.(?) The 11 splatter monsters are those X-Force type class c amplifier in my opinion. They barely bother me from one channel below my home, but I believe yy Madison and sonar to have far superior adjacent Channel rejection then most if not all of the locals that hang out on the same channel as me. Most of them are using exports. When the locals one channel below begin modulating all my locals using those imports get hammered. They can't even hear stations that are 5 miles from their house. And the guys 1 channel below using those class c amplifier are 25 miles away. I get one or two s unit of splatter while my locals using those exports have told me they're receives are absolutely wiped out. I hate to get off subject, but I don't think I will ever own an export radio. not only for the reason I mentioned but many others. I enjoy the sonar as my AM station, and the Madison as my SSB, and couldn't be happier. 73. PS happy holiday to you and your family captain. I hope you have a terrific one. Your friend 111 joejoe South Jersey.
Most of the older well made amps are class ab and will not splatter when properly driven. I remember seeing many ads for them in radio magasines especially from the UK. They were well made and looked nice not like most today that are thrown in a piece of diamond plate aluminum cases or such.Most 11m amps today are class C and will splatter like hell on the bands. Then again most people don't care and operate them anyway.
I am familiar with the the fact that d&a, Maco, Palomar, and most of the amps built during the craze are AB biased. What I didn't know was that the ab biasing produced a clean signal (taking into consideration how it's driven, and the transmitter driving it.) I always hear how there's no filtering excetera excetera excetera, and that the amplifiers built by the company's I mentioned above are nothing more than junk splatter boxes. I always find it interesting when I read those who continuously write how poorly these amplifier were built, and how much splatter, and second harmonic RFI they cause. My surprise is caused due to the fact that I have never had any of those issues with my Phantom, 300a, 350Z, Maverick, and several others. I didn't receive complaints back in the late 70s through the mid-80's and I've received 0 since my three years back on the air. So, are they as bad as most portray them to be? Or is it the fact that they use sweep tubes, and obviously lack many of the components that are high-end amplifier contains? Do people complain just because it's an 11:00 amplifier, or are they, or are they justified in their constant whining? There's obviously no comparison in build quality between a black cat 2000 and a SB220 except for the fact that they both use twin 500 Z's. Yet the black cat 2000 which was used by a local of mine back in the day caused little to no splatter, and never received complaints from neighbors. He ran that amplifier with a Cobra 2000 for approximately 15 years without a single neighborly RFI complaint, and very few splash issues. The people complaining of splash while he was running the black cat 2000 where those within a 5 or 10 block radius. I'm assuming the same type of splatter would be expected from an SB 220 from people in that same general radius. Is someone going to cause absolutely no splatter to a local within a mile away if he were to be using one of a legal limit higher-end HF amplifier?. Acon, Drake, Ameritron, HP Tokiyo?
The amount of splatter depends on a lot of things such as bias, drive levels, and how clean the transmitter is as well as just how well the receiver on the other end can handle high RF levels. A properly driven AB class amp driven by a clean TX should be quite clean on the air. Amps with sweep tubes have poor IMD and may sound great on-frequency but may have some splatter on the band if driven hard. Whether a tube amp has low pass filtering or not is almost moot since the tank circuit itself is actually a filter. This is one reason people claim that tube amps are cleaner than transistor amps. ANY solid state amp would benefit from a low pass filter but that will only clean up harmonics and do nothing for bad IMD or splatter caused by being class C.
"I think the biggest drawbacks when using a true amateur radio amplifier on 11 meters. is if your not using a (Mars) modified HF, or a 50+ watt modified export you're going to need a separate driver, and a foot switch."
If you leave the Accu-Splat! driver out of the situation, and put your carrier at ~4 watts, a "ham" amp works wonderfully, and generally won't put out more than 30-50 watts MAX, pretty much guaranteeing you won't be working the neighbor's toaster, audio system or television.
I understand your disability, as well, but with a little technical wizardry, a RF-sensing circuit could certainly be built for one of those monster LEENYERs as well.
73 de ButtFuzziness.
If you leave the Accu-Splat! driver out of the situation, and put your carrier at ~4 watts, a "ham" amp works wonderfully, and generally won't put out more than 30-50 watts MAX, pretty much guaranteeing you won't be working the neighbor's toaster, audio system or television.
I understand your disability, as well, but with a little technical wizardry, a RF-sensing circuit could certainly be built for one of those monster LEENYERs as well.
73 de ButtFuzziness.
Madison, PC-412, 200 et all , pin 8 mb3756 (emitter tr31?) goes high in TX.
I used a 12v small frame relay for years in a 142GTL bot didn't use the mb3756 for AM collector supply. In the 148GTL I used a 5v relay. The opto iso would be a better idea but I wasn't that smart years ago ...
LH1540AT opto iso should be able to handle the amp relay and protect the radio.
I used a 12v small frame relay for years in a 142GTL bot didn't use the mb3756 for AM collector supply. In the 148GTL I used a 5v relay. The opto iso would be a better idea but I wasn't that smart years ago ...
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