Since you don't have control of the audio level anywhere else, I would suggest using a potentiometer as the attenuator. Hook the output of your remote base audio to both ends of the pot, and take the input to the TS-440 RCA jack from the center lead of the pot. Hook the ground end of the pot to the ground from the controller and to the ground on the RCA jack. A 10 K pot should give you all the control you need to set the levels. Typical convention is to let the clockwise rotation of the pot increase the level, so use the correct terminals on the pot to give this action.
73 - Jim W5ZIT --- On Mon, 8/11/08, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> Subject: [Repeater-Builder] ACC RC-85 / Kenwood TS-440S Remote Base Questions To: [email protected], [EMAIL PROTECTED] Date: Monday, August 11, 2008, 11:17 AM I have a UHF Repeater using an ACC RC-85 repeater controller, which also controls a Kenwood TS-440 HF Transceiver as the Remote Base radio. All the HF Radio control commands seem to work fine, except the "Bump Down 500 Hz" command. The command is "[Remote Base Prefix] 7" - it just has no reponse. But the "Bump UP 500 Hz" and the other "Bump Up/Down" - 20 Hz and 100 Hz step commands work just fine. It's not a problem decoding the "7" - the Touchtone Pad Test reads back all digits correctly. The touchtone decoder in the RC-85 seems to work extremely well and decodes noisy signals without falsing. I can be mobile, using just a handheld radio that's choppy into the repeater, and dial around on the HF radio with hardly ever having a missed digit. The other minor problem I'm having is that the transmit audio for the TS-440S is so hot coming from the RC-85 that it's unusable. The output of the RC-85 transmit audio is fixed level, and is controlled by the inputs from the receiver (in this case, the UHF repeater receiver.) If I turn down the level of the receive audio to the controller so that the TS-440 transmit audio is at the proper level, then the controller doesn't have enough audio output to drive the main UHF transmitter to more than about 2 kHz deviation. I'm feeding the transmit audio into the TS-440's "AFSK IN" rear-panel jack, as suggested in the RC-85 manual. Using this input, the TS-440 front-panel mic gain control has no effect on the transmit audio level from the AFSK IN jack. Looking at the RC-85 manual and in an old issue of "ACC Notes" which describes RC-850 and RC-85 transmit audio level setting procedures, it suggests padding down the output of the transmit audio using an attenuator or resistive voltage divider. Anyone tried this and have any starting values? Lots of fun! Larry K7LJ __.__
