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No you can't expect to get 75 watts PEP from a 2SC1969. You might get close to double it's rated power someplace around 40 watts PEP for intermittent use. I wouldn't count on it being very reliable either. This mod Toll Free has shared is more of an audio mod then a power mod. If you're going to do any mod to a radio it should be to improve audio, not increase power.

Even these new bolt on heat sink final replacements that claim 75 watts overlook an important problem for hi level AM use. Radios that use the modulation transformer get their audio directly from the audio chip with no buffer. Ask the 4 watt radio to key 8 watts and you need twice the modulation power from the audio chip because the current has doubled. This happens as a result of the final collector impedance dropping in half.

Then you have to consider that poor little modulation transformer having to support twice the DC current on it's secondary while it's primary overloads the audio chip to the point where it probably flat tops on positive peaks. The extra current on the mod transformer will cause more distortion in your low end due to core saturation.

The point here is if you want the best audio on AM, don't modify your radio to produce 2 to 5 times it's original carrier and still expect to have the headroom required to reach the positive peaks this type of mod can do. This mod should let you run over 100% modulation without noticeable distortion and with a significant decrease in bleedover.

<blockquote data-quote="Shockwave" data-source="post: 253440" data-attributes="member: 10882">No you can&#039;t expect to get 75 watts PEP from a 2SC1969. You might get close to double it&#039;s rated power someplace around 40 watts PEP for intermittent use. I wouldn&#039;t count on it being very reliable either. This mod Toll Free has shared is more of an audio mod then a power mod. If you&#039;re going to do any mod to a radio it should be to improve audio, not increase power.Even these new bolt on heat sink final replacements that claim 75 watts overlook an important problem for hi level AM use. Radios that use the modulation transformer get their audio directly from the audio chip with no buffer. Ask the 4 watt radio to key 8 watts and you need twice the modulation power from the audio chip because the current has doubled. This happens as a result of the final collector impedance dropping in half.Then you have to consider that poor little modulation transformer having to support twice the DC current on it&#039;s secondary while it&#039;s primary overloads the audio chip to the point where it probably flat tops on positive peaks. The extra current on the mod transformer will cause more distortion in your low end due to core saturation.The point here is if you want the best audio on AM, don&#039;t modify your radio to produce 2 to 5 times it&#039;s original carrier and still expect to have the headroom required to reach the positive peaks this type of mod can do. This mod should let you run over 100% modulation without noticeable distortion and with a significant decrease in bleedover.</blockquote>

[QUOTE="Shockwave, post: 253440, member: 10882"] No you can't expect to get 75 watts PEP from a 2SC1969. You might get close to double it's rated power someplace around 40 watts PEP for intermittent use. I wouldn't count on it being very reliable either. This mod Toll Free has shared is more of an audio mod then a power mod. If you're going to do any mod to a radio it should be to improve audio, not increase power. Even these new bolt on heat sink final replacements that claim 75 watts overlook an important problem for hi level AM use. Radios that use the modulation transformer get their audio directly from the audio chip with no buffer. Ask the 4 watt radio to key 8 watts and you need twice the modulation power from the audio chip because the current has doubled. This happens as a result of the final collector impedance dropping in half. Then you have to consider that poor little modulation transformer having to support twice the DC current on it's secondary while it's primary overloads the audio chip to the point where it probably flat tops on positive peaks. The extra current on the mod transformer will cause more distortion in your low end due to core saturation. The point here is if you want the best audio on AM, don't modify your radio to produce 2 to 5 times it's original carrier and still expect to have the headroom required to reach the positive peaks this type of mod can do. This mod should let you run over 100% modulation without noticeable distortion and with a significant decrease in bleedover. [/QUOTE]

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