Recent content by nomadradio

The amplifier is definitely wired to place operating bias on the RF transtors. The question is whether or not it works properly. If the sideband audio sounds worse with the mike gain turned way down than it does turned up, you need more idle current on the transistors. This amplifier has fixed...

I had good results from his replica VCO modules. Odds are you will too. 73

And never will be. At least we aren't seeing the 30-dollar Coca-Cola from Back to the Future three. 73

The aisle in a supermarket that sells laundry detergent will offer multiple brands, and more than one 'flavor' for each brand. The number of chemical factories who actually make all that stuff is around 2 or 3, total. Packaging, promoting and marketing laundry detergent is a whole separate...

The dot scans from left to right at a rate that makes audio signals legible. An RF waveform naturally moves up and down way too fast to separate the ups and downs of the waveform. Makes the "luminous band" trace this way. Naturally if you speed up the horizontal time base to a microsecond or...

I know we converted at least one type 6 to a type 3. I'll see if I can dig up some pics. 73

Version six is sort of an orphan. They were dreaming to try and make it stable at 23 MHz. All the other models run at lower frequencies and drift less. The schematic for the 6 is different, so the widely-published schemo show capacitor values for the various versions, but skips from version 5 to...

Should match up with the Galaxy DX11B schemo from CB Tricks. Pin 54 is receive-only 8-Volt power from R141. If the red wire goes to the clockwise lug of the rear half of the clarifier control, this is where it was connected. To make the receiver and transmit frequencies "lock" together on the...

Since the PLL is a DC circuit, set the vertical position knob to put the baseline on the bottom line of the screen. For the 5-Volt PLL circuits, set the Volts/div knob to .1 if you're using a times ten probe. The red inner knob turns full clockwise. Pretty sure it clicks all the way to the right...

Get 'em hot enough, and the flavor of the solder won't matter. A tube with a brown bakelite ring under it offers a clue when the brown turns dark around the two filament pins. 73

Okay, so I've lost track of this thread. Just what fault are we chasing? 73

Nothing a trimpot with a high enough resistance can't cure in series with the meter coil. 73

Can't assume there is only one cause. That capacitor needs to be soldered in, for sure. Once it's connected, it should be peaked for max modulated power NOT just the silent carrier. How much carrier do you have coming out of the radio, and how much coming out of the amplifier? The MRF455 is...

Holy moly! Open source to the rescue. 73

Google is your friend. On a good day, at least. Only offered me one source today...