| Author |
Message |
    
Balasco
| | Posted on Saturday, May 19, 2001 - 11:23 am: | 
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I would like to know which gives you better audio
and over all performance a tube amp or transister amp for base |
307 (307)
| | Posted on Saturday, May 19, 2001 - 7:23 pm: |
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Tubes by far. They are much better because of several reasons. Transistor amplifiers are broadband and splatter (TVI). Tube bases are more narrow and must be tuned. This gives a much better signal output RF less all the RFI (Radio Frequecy Interference). |
Kf4gyp
Junior Member
Username: Kf4gyp
Post Number: 24
Registered: 11-2009
| | Posted on Monday, December 13, 2010 - 4:50 pm: |
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This is my opinion. I think I like the transistor based amps dew to the fact I never need more than 50 watts to talk an average of 50-60 miles in about any direction when talking local. So I need to produce very little heat. Thing is no box will ever create more than what is being fed into it in other words trash in trash gets bigger and fed on to the antenna, clean in clean gets bigger and sent to the antenna. I have yet to see a box of any kind do any thing without a radio connected so that said run what ever you want. transistor types produce less heat and if not abused will last longer than any tube on the market due to the filament life. So pick one be very conservative on the radio out put and have fun!!
After all that is what this is all about any whooo.
Thanks Ray
73 Ray/Hawk-Eye
DE KF4GYP
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Charliebrown
Intermediate Member
Username: Charliebrown
Post Number: 148
Registered: 10-2002
| | Posted on Saturday, January 08, 2011 - 9:13 am: |
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I have friend's that use tube amp's and they do splatter as well. If your radio has nasty harmonics it will amplify the nasty. Clean up the radio to clean modulation that is not past 80% and the amp will not splatter as bad. The same goes for the transistor as well. They both only amplify the source , Kf4gyp had said the same also and I believe he is right. |
Onelasttime
New member
Username: Onelasttime
Post Number: 5
Registered: 8-2011
| | Posted on Saturday, August 06, 2011 - 8:18 pm: |
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I know this is an old post but I stopped to read it so maybe other's will too. I disagree with the idea of transistors being longer life then tubes. In a base amp tubes can easily last 25 years or more if tuned and loaded properly every time you use them. As for power consumption that is legit concern they are not as miserly with energy as transistors.
Even sweep tubes never intended for amplifiers that where built for TV set's can last 15,20,25 years.....The ceramic tubes designed for RF circuits those are vastly superior and more long lifted then regular sweep tubes. The most powerful RF amplifiers on earth use tubes. The 4 driving 1 ULF set at Pearl Harbor has been in place for a long long long time and I think that is some where between 50,000 and 80,000 watt's at wave lengths so low that we are talking about 1/4 being measured in kilometer's....LOL
It is mechanical abuse that tubes usually can not take as well as transistors so vibrations mainly.
Tubes are not for idiot's or lazy people so if you are stupid or lazy go with transistors other wise consider tubes for a base. Tubes do not tolerate mistakes in tuning and loading or drive!!!
If you look at a two guys transmitting on exactly the same gear other then amp but equal output power the guy on the tube amp will 99% of the time sound better. Sound quality is better because Japanese transistors are usually overly biased for high output creating a harsh metallic sounding audio.
Another example I talk a lot of side band so inter mod number's are important to me tubes tend to have lower number's then the Japanese high power RF transistors. Like wise American transistors like the MRF 455 have less output but better inter mod and hence sound better. A 2XMRF 455 amp will sound better at it's clean RMS setting then a single pill 2SC2879 amp even though the power output is almost identical. The 2SC2879 will require slightly less power in terms of amp draw then a two pill amp and it wil tolerate higher SWR then the MRF 455 but it will not sound as good on AM and especially not as good on SSB. So even when looking at transistor amps their is more to look at then output power, heat and energy cost!!!
For the record you can drive a 2879 with 4-12 watts so you can build a single pill 2SC2879 and drive it with a CB radio. I owned a home made single pill amp that had 1 2879 in it.
Personally I wish someone would build things like a sweet 16 but with MRF 455's for instance....LOL For some reason no one seems to use that transistor anymore.
Their is a reason why so many people love the KLV-1000 tube amp. Like wise if you look at 90% of the legal limit amps for Amateurs most of them are tubed or some form of combo with a transistorized power supply control, band tuning and driver but tubed final stage etc....
Also when you start using transistorized mobile amps in your home you also need a power supply with enough amperage to run them. That add's tot he lower price you pay for the mobile amp. I have not tried one of the lower power base type transistorized amps but I would assume that their power supply if built in is just barely up to the job and might not be the cleanliest supply on the planet.
As too the heat one advantage to tubes is that usualy they will forgive being over driven more then a transistor will. So if you forgot to turn your rig down and you notice your tubes are glowing like mad and tossing off heat you know you need to turn your drive down....If you forget to do that with transistors normally they will pop like a fuse rather quickly and smoke comes out of the amp!!!!
Ultimately it is not going to matter because abusing either in the end will shorten the life span. I think that tubes sound much better on AM and SSB then transistors do.
IF we where talking about mobile use well I would go with transistors first because they are more efficient and unlike my home where I have unlimited power a car or truck has sever power limitations both in batteries and in the supply side from the alternator!!! Anything more then 100-200 watts in car and tubes would just kill you in a hurry. Also with all the carpet, vinyl and plastic in car's today finding a place to mount a tube mobile amp that will not catch fire or melt can be an issue even transistors get hot. But most of us do not expect the same level of fidelity in a mobile set up as we do a base station! |
Tech833
Moderator
Username: Tech833
Post Number: 2018
Registered: 8-2002
| | Posted on Sunday, August 07, 2011 - 12:08 pm: |
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Where did you copy this from? Proper credit should be given to the author.
Your radio 'Mythbuster' since 1998
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