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VCO Buffers, carrier oscillators, driver/final bias drifting, RF stage not aligned properly. All these will affect output. Do a complete alignment, paying close attention to results.
Like nomad said, if any of those silver cans are topped out (core flush with top) or bottomed out (core flush...
No problem Krazy,
Hope to hear you in skipland sometime.
On CB I hang on channel 40 AM, 29 AM, sometimes channel 1 AM and I go by 351 around the Carolinas.
Peace...
I see a "simple swing" mod also in the top pic above. This simple swing mod I see no problem with, I use it myself also at times. But in order to go back factory I would remove it.
The one I'm referring to is located right in front of VR13 (AM HI deadkey adjustment). It's marked as R238...
See those resistors around D83 in the first pic above? There are two laying flat (not standing up). One of those is R249 (it's marked on the board). It looks to be connected, so no worries.
If it's swinging 40w max, then turn the RF power knob all the way up, and adjust VR13 for a 9w or 10w...
Things to check:
R238, make sure it's just a 5.6k ohm resistor. Not a diode and resistor. Some people will place a diode on one side of this resistor to allow the radio to swing to max peak regardless of the carrier level. Can be aligned out to look good on an oscope and spectrum analyzer. Not...
Works on a 2547 also. Just installed a VFO windup on this 2547 for a local friend of mine, works great, even with clarifier button engaged it still works and settles dead on frequency.
1000uf 25v 105° electrolytic capacitor.
Tie positive lead of cap to wiper (flapper, lol) pin of the xmit...
R216 should be a 1 ohm resistor. Also, are you sure the final that vr10 feeds is good? If a final is bad, you won't get any reading on your ammeter when setting bias. Check the collector voltage on the center lead of said final while keyed up (meter in volt mode).
R216 = 1 ohm (Brown, Black...
Also, this little coil in the rear is actually two coils butted against each other. Most people don't notice it as being two coils. These must be separated so as not to touch as seen in this photo. Yes, this coil does affect output. Closed = less, seperated in center only = more. Only seperated...
I basically just gave you (above) everything I do to these 3600 boards to get the max performance without harming other parts by heat buildup or creating any harmonics. Besides the alignment steps I go by. Tip: the VCO Buffers and oscillators are the trick (not secret) to receive and transmit...
As for the growling noise, could come from several spots. My experience with the growling while the echo board was connected turned out to be a bad echo board which shorted out the mic op amp (4558). Bypassed the echo board completely, replaced the mic op amp and the growling was gone.
Hope the...
Tip for better average swing on all the 3600 boards. Check/replace C133 (10uf 16v). I recommend replacing this cap with a 4.7uf 25v cap. This is the AMC Timing Capacitor. The factory 10uf is a little to aggressive (limits average swing). Also, strap a 22k ohm resistor across this caps leads on...
Wiper is actually what I heard handy and them call it, I was mistaken on who I got the flapper term from. But like cable guy, it's sounds funny so I'm gonna stick with flapper, the word puts a giggle in me also when I say it, lol
Well, tied the positive lead of the cap directly to VR7 flapper. Ran a wire from negative lead of cap to switch in the rear, ran another wire from switch to ground. Settles on frequency on AM with switch on and is dead on frequency with switch off in AM and SSB.
SSB seems odd with the switch on...
Was just thinking about that.
I was also thinking of how I can determine if it's the wire or switch that's causing it. I figured I could just tie the flapper wire and positive lead of cap together at the switch end of the radio and see how far it goes before setting. If it settles on frequency...
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