| Author |
Message |
    
Oklahoma 428
| | Posted on Thursday, July 26, 2001 - 10:35 pm: | 
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I was told by a fellow cb'er that you could make a dummy load from a 40 watt light bulb and a 3 foot piece of coax. Would it be worth it to try or would it mean I might have to order a new set of finals?! |
Tech181 (Tech181)
| | Posted on Thursday, July 26, 2001 - 10:58 pm: |
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Oklahoma428,
The impedence of the lightbulb, well actually the filament, changes as it gets hot. So you won't get an accurate reading and you might be buying a new set of finals.
Steve
Tech181
Tech181@copperelectronics.com |
bruce
| | Posted on Friday, July 27, 2001 - 7:05 am: |
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the light bulb impedence changes as the drive to it changes it goes up as the bulb gets hoter tech 181 is correct now if you want to make a fairly good load get 20 2 watt 1000 ohm carbon resistors parallel them to give 50 ohms this would handle 40 watts i dont think you would save any money over buying one but you might use it as a learning project
bruce |
Anonymous
| | Posted on Saturday, July 28, 2001 - 4:44 pm: |
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Or you could go to radio shack and buy one for 21.95 |
bruce
| | Posted on Saturday, July 28, 2001 - 9:52 pm: |
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Yea but its more fun to build one for 30 dollars no your right but building would be a learning thing not cost saving |
bullet
| | Posted on Sunday, July 29, 2001 - 11:59 am: |
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ive done this and like bruce says its more fun building one your self.i used 1 watt resisters
all they had(rat shack)at the time,its good for 20 watts . |
Oklahoma 428
| | Posted on Sunday, July 29, 2001 - 1:30 pm: |
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Thanks guys! :-) |
Roger
| | Posted on Tuesday, September 25, 2001 - 11:33 pm: |
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A long time ago I once had a store bought dummy load and it had a small light bulb in it. It appeared to be a bulb like you would use for a fender light for a car or truck and it worked very well. I just cant remember what I did with it. Surly there is a bulb that once the filament got hot on a stock radio it would give a good swr??????? 307 this sounds like something you should comment on. I realize buying one would be simpler, but for a tech. like your self, It should be a snap! |
BamBam_138
| | Posted on Sunday, September 30, 2001 - 7:06 am: |
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307 is right the fillement in the bulb heats up and swr changes,If you had a bulb to handle it you could set your swr after it warmed up but who wants to warm a light bulb to tune a radio ,buld the resistor load or buy one,And don't buy one with a bulb in it ! This fella got took ! BamBam_138 |
doctor bleedover
| | Posted on Friday, October 05, 2001 - 2:47 pm: |
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i have been using light bulb dummy loads for years to work on cb radio's.some i bought but now i make them out of a 12 volt bayonet style bulb available at radio shack.i file the lugs off the case and solder a wire to the bottom of the bulb.then shove it into a pl 259 and solder the wire to the center of the 259 and tack solder the case to the shell.
its handy and works well for me.i have also used 100 watt light bulbs for working on linears .
my b& k 374a dummy load is more accurate but cost a lot more money. |
