solid state 200

[1iwilly]

looking for a schematic for a solid-state 200 base amp i need to know which resistor to change for the dead key i have to have my radio at 1/2 watt in order to make it dead key 90 watts if i can increase the resistor then i can bring my radio to 2watts to still make amp dead key 90 watts

 

[nomadradio]

It's an orphan. I'm told it's a "Gray" amplifier. Might be. Never was a diagram that escaped into the wild for that one that I know.

Never needed one, really. It's pretty simple. Biggest drawback was the power supply. Unregulated, would put over 20 Volts on the RF transistors in standby. Dropped to more like 12 or 13 Volts under load while keyed up. That 20 Volts would tend to assassinate RF transistors if you got them a little hot. Used a stopgap that placed a 30-Amp automotive relay between the power supply and amp board, wired to the keying relay. Only put DC power to the transistors when they have RF drive, draw current and pull the supply voltage down to the safe range. The power transformer is so undersize that it eventually overheats and fails.

There is no fixed bias source for the RF transistors, so sideband will sound like doo-doo.

If the resistors on the high/medium/low switch are burned up, either they were too small, or someone used a radio that was too big.

Or both. Seems to me we used an example from the schemo of another amplifier to replace resistors burned beyond recognition.

Here's one. Has three levels. http://73.235.100.209/Amp/palomar_other/elite/pal_hd400.gif

Learned to put a SWR meter and coax jumper between the radio and amplifier to make sure the amplifier's input SWR doesn't get out of hand.

A carrier power of 30 to 50 Watts is more realistic for a small 2-transistor amplifier. Probably won't sound so good at a 90-Watt carrier.

73

 

[1iwilly]

It's an orphan. I'm told it's a "Gray" amplifier. Might be. Never was a diagram that escaped into the wild for that one that I know.

Never needed one, really. It's pretty simple. Biggest drawback was the power supply. Unregulated, would put over 20 Volts on the RF transistors in standby. Dropped to more like 12 or 13 Volts under load while keyed up. That 20 Volts would tend to assassinate RF transistors if you got them a little hot. Used a stopgap that placed a 30-Amp automotive relay between the power supply and amp board, wired to the keying relay. Only put DC power to the transistors when they have RF drive, draw current and pull the supply voltage down to the safe range. The power transformer is so undersize that it eventually overheats and fails.

There is no fixed bias source for the RF transistors, so sideband will sound like doo-doo.

If the resistors on the high/medium/low switch are burned up, either they were too small, or someone used a radio that was too big.

Or both. Seems to me we used an example from the schemo of another amplifier to replace resistors burned beyond recognition.

Here's one. Has three levels. http://73.235.100.209/Amp/palomar_other/elite/pal_hd400.gif

Learned to put a SWR meter and coax jumper between the radio and amplifier to make sure the amplifier's input SWR doesn't get out of hand.

A carrier power of 30 to 50 Watts is more realistic for a small 2-transistor amplifier. Probably won't sound so good at a 90-Watt carrier.

73

nomad, the dead key from my radio is 1/2 watt that 1/2 watt dead key gives me 80 to 90 watts dead key out of the amp i want to know which resistor in the amp on the high side to change so i can bring up my dead key on my radio to at least 1 1/2 watts RMS. and at the same time try to end up with like a 75-watt dead key coming from the amp too ??

 

[AudioShockwav]

Looking at the schematics for the hi/med/low switch, it looks like a 27 ohm on the power switch for low, 150 ohm for med and no resistor for high.
These resistors bleed off some of the signal to lower the output.
Can't you just run the amp on medium or low to drop the dead key?
Adding a resistor to the high setting to bleed off some drive is the same as switching to a lower power level.

73
Jeff