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STEPPING UP FUSE 25 TO 30

Stellasstillarat

Active Member
Aug 14, 2014
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The amp I thought I fryed, wasnt fryed after all. After opening the amp i noticed one of the two 25 amp fueses had blown out. I replaced it with a buss 25 amp (it takes the old type glass fuses). I shot some ssb skip no problem. The d104 is turned all the way up as I use the radios mic gain to adjust the audio. I leave the mic gain at 12 o'clock. The amp worked great. 7 hours later I turned the amp on had a qsl with a local, a contact came over from a distance. I turned the pre amp on and turned the radios mic gain to about 4 o'clock.while adding audio On my third key down the amp shut down. Sure enough the same fuse blew out. Can I up the 25 amp fuse to a 30 amp fuse or the audio output with the mic gain at 3 o'clock is just to much for the amp. 2 1/2 swings to 5 with the mic gain at 12, at 3 o'clock it swings to 8-10. Might that be to much for the amp or to much for the fuse? If uping the 25 to 30 anp fuse will alow me to turn up the gain now and then without damaging the amp great but if there's a chance the 5 more added amps will cause the fuse not to blow out and the amp to fry, I will keep the 25 amp. I will have to live with the fact that the mic gain can't be turned any higher than 12 o'clock. the amp is a 500 watt with a built-in 12 volt 35 amp power supply, base. I don't even know if these are the fuses that belong in it as it's an older amp and may have past through many hands. If any one has a Palomar/bommer/ silver star 500 elite and has the schematic and knows if 25 amp is the correct size fuse, please let me know. I down loaded the free schematic but it all Greek to me. theres also a third fuse for the 12 volt power supply. It's located outside of the back of the amp, its also a 25 amp fuse.
 

Try using Slo-Blo fuses before you add a higher amp fuse. See if you can find a schematic of your amp. Most schematics will list the amperage of the fuses. I looked at one amplifier on CBTRICKS-COM and one unit had 35 amp fuses in it.
 
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OK I did a search on the palomar 500 elite .4 x mrf 455 pills will pull a lot more than 25 amps . You will need a 35 amp fuse or you could use the 30 to be safe.. As for the third fuse I presume that is in the mains side of the transformer and if it is it should be only 5 or 6 amp.( remember the transformer steps the volts down so the amps go up. Ohms law v= i x r) so if it has a 35 amp output the input will be much lower.Check the location of the third fuse.Hope this helps .
 
Found a schematic unfortunately it only shows one 20 amp fuse F1 on the mains side of the transformer and none on the dc output. You should not increase this value of this fuse, as I said earlier if anything it should be lower.
 


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