Ok, had to put that in there so you can make your own stuff separately - refer to that post.
This one is done so I can help you with something that can get complex - using a separate post...
Ok, without too much detail...
L23 and L24 also provide 1/2 of a signal to the TX side too...
But the other HALF of that signal is where L19 comes into play...
So, for overview,
- L24 is PLL's main clock and system timing - adjusting L24 adjusts EVERYTHING timing wise...
- MEANING - NO PEAKING - DOES AFFECT RX and TX FREQUENCY
- L23 is IF for 2nd IF 10.240 Down mix of 10.7MHz to 455kHz
- L19 is PLL's TX frequency to be mixed with L23's at IC3
- IC3 power Mixer and uses L21 as a Bandwidth Peaking filter
- L21 is a DUAL coil and both coils peak TX frequency to CB band
- IC3 sends this new mixed 27MHz signal to L20
- L20 then Peaks for Predriver and sends it into L17 for Driver to process...
- L17 is PREDRIVER's input signal to be amplified - forms weak carrier.
- Driver (Behind Heat Sink Panel - Mounted to it) Amplifies Carrier from Predriver and adds in Audio and Bias from REACTANCE MODULATOR - as Collector (Plate) Modulation.
- Final Amplifies Driver Signal output further and uses Same Collector (Plate) Modulation and sends it to Tank Circuit that L14 Peaks and then to output network and Antenna connector
Let's get back to that one picture with all the diagrams and flowcharting and see if that can help guide you further...
I've added more to it...It's complex, but you only need to know L23 and L19 and L21 work with IC 3 - see below...
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Study that for a moment - this is where all the INTERMEDIATE frequencies of the Radio begin (Originate), get Generated, Mixed and or go to be processed
Look For VR 4 and VR 5 they handle some stuff back there by the Big Transformer your Reactance Modulator - if you don't SEE RF on your internal meter - this VR pot (VR5) may be turned the wrong way.
L19 is output of PLL to TX, start peaking that...
Then Look at L21 for Tweaking it - Both coils affect the other so be careful...
- Know too, that L21 is BANDPASS so one coil tends to work a group of channels on one side of the band - while the other coil in L21 tends to work the opposite side of the band - together you make an AVERAGE Peak response of power across them - they go into L20 for the Pre-driver to work with.
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Work in Increments...Rome wasn't built in a day....
Install Dummy Load and Power Meter
- set it properly for Power in Low-wattage range
- with Dummy load on Antenna jack of the Meter
- and Coax Cable hooked up to radio and Meter properly
Use Properly Wired Microphone
Set Up Monitor Radio on Same Channel As Radio Under Test
TX RADIO INTO Meter/Dummy Load and only for short moments to check and adjust slugs to verify RF Power is building and continue doing this as you peak out the system - also LISTEN FOR CARRIER ON MONITOR Radio
If you have not already done so - get one of these tools - a CERAMIC Tip Slotted Tool...like this...
[ATTACH=full]35939[/ATTACH]
It's Handy...
Allows for Smooth Retuning of IF cans...
Won't Stick To Most Dental Work.
- Starting on Yellow Coil of L21 - slowly turn the full length of the bobbin to find meter movement and show RF power
- Increment other Coil Bobbin and re-do step above to see if RF power can build
- Are you Listening?
- Are You Watching Meter?
- Tweak L17 and L19 - L20 together as you Look for Wattage to move the needle
- Work In Small steps
- Work Along TX Strip of L20 (Predriver), L17 (Driver) and L21 (Balancer)
- Unkey Microphone - Check for Heat - Rest yourself too
- Repeat As Needed
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"...Small Moves..." - Contact
Pretty soon, you'll be making your own Contacts
