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Ferd_burfell
Junior Member Username: Ferd_burfell
Post Number: 13 Registered: 6-2006
| Posted on Thursday, July 06, 2006 - 10:45 pm: |
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I have 2 of these radios - 30w & 100w. The 100w radio has 2 pots that are black plastic instead of the usual metal - 1 is the AMMOD & the other is the middle pot of the 3 behind the metal shield in the back left corner (bottom cover off facing up of course). What the heck are they doing there? Anyone know? They're not military trimmers that turn & turn & turn - they travel like a regular pot. Any ideas? This radio appears to have been "RAMBOIZED" by some brain surgeon with the ALC removed to an external knob etc................... I could go on. |
Ferd_burfell
Junior Member Username: Ferd_burfell
Post Number: 15 Registered: 6-2006
| Posted on Friday, July 28, 2006 - 4:58 pm: |
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There's 2 or 3 knowledgeable AR3500 lovers here in the forum - I'm surprised none can answer my question, |
Patzerozero
Senior Member Username: Patzerozero
Post Number: 3121 Registered: 7-2004
| Posted on Saturday, July 29, 2006 - 10:02 am: |
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the 3 pots to the left rear corner are labeled VR14, 12 & 13 left to right in that order. VR14 is the driver bias, VR12 & 13 are final amplifier bias. TRANSMITTER - SSB MODE 1. - Set radio to 28.0000 Mhz. on SSB mode. 2. - Set "MIKE GAIN" to minium and adjust VR-9 & VR-10 ( Balanced Modulator) for minimum RF output These controls should be balanced for even output on LSB & USB. IF ADJUSTMENT IS REQUIRED AT THIS STEP THEN REPEAT STEP 6 OF PLL-VCO ALIGNMENT. 3. - Set "MIKE GAIN" to Minimum, MODE to LSB TX. Connect DVM to ferrite bead side of R- 198 and ground. Adjust VR-14 for 0.68 VDC (Driver Bias.) Move DVM to ferrite bead side of R-190 Adjust VR-12 for 0.68 VDC ( Final Amp Bias.) Move DVM to ferrite bead side of R-194 Adjust VR-13 for 0.68 VDC ( Final Amp Bias.) NOTE : After VR-12, VR-13 are adjusted, Re-Adjust VR-14 for best swing. VR16, the AM power control is what should have been moved to an external control to have variable rf power. VR17 AMC VR15 ALC VR11 RF output/meter VR9 & 10 balanced modulator VR7 & 8 S meter(FM &SSB) VR4 FM deviation VR 1,2,3 USB, LSB, AFC for synthesizer alignment all of the AR3500's i have, 30 & 150 watters, have old-style metal pots there. maybe the plastic ones in yours were replacements at one time? |
Ferd_burfell
Junior Member Username: Ferd_burfell
Post Number: 16 Registered: 6-2006
| Posted on Saturday, July 29, 2006 - 12:24 pm: |
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Thankyou very much for your prompt reply. When I said above that "I could go on..." VR16 was one of those things - it's also been moved to an external control. I appreciate the alignment info - I have that, BUT THANKYOU for posting it. The last part of your reply is what I was looking for. I'll be sending my 100w radio to Bob's CB soon - the recieve does bad things: works fine, then attenuates A LOT, then...mostly attennuated. Anyway, thanks for the info. N4AVL |
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