RRC voltage provided to TS-480 control head

[K4FWJ]

The TS-480 control head obtains its operating voltage via its RJ-12 jack.  Therefore when used with RRC the RRC control box must provide it.  On Page 115 of the TS-480 service manual the voltage required for proper operation of the TS-480 head is shown to arrive on Pin 5 of J2.  Internally, this line is identified as 8M.  One of the first places 8M goes is Pin 1 of voltage regulator IC6.  The Kenwood service manual stipulates that voltage is to be 9.25v.

Instead of the RRC control box providing 9.25v +/- 5% or even 10%, the Microbit instruction manual shows the voltage supplied will be 8v.  On my control box I have verified the no-load voltage to be only 8v.  This is almost 15% less than Kenwood engineers stipulate for reliable turn-on and proper overall TS-480 operation.  My question is how can this be considered desirable and/or acceptable?  Art

[sm2o]

It's no big deal as it's only the backlight LEDs which is powered by the 8/9 V but if you remove JMP2 you get 9V to the front panel.

73 de mike

[K4FWJ]

Yes, the raw 8v is used for the backlight.  But it also goes to 5v voltage regulator IC6.  It looks to me like that 5v is the principle operating voltage for the remainder of the head circuitry.  We all know a voltage regulator must have a minimum input voltage in order to reliably maintain its specified output.  Kenwood has specified that voltage to be 9.25v.

I removed the jumper on JMP2 and it made no difference - the TS-480 still refuses to turn on.  I did not verify an increase of 1v on the 8v line - will take your word for it.

The TS-480 body back home is responding normally to all HRD and DXLab commands - if and only if RRC control Auto Connect is set to "on".  From N.C. I have worked some EU stations via the TS-480 body in Florida.  Some success is better than none at all.   

[sm2o]

The auto connect option is there to be used when the boxes are used to replace fixed 2 or 4 wire leased lines in commercial systems not in this case. Your problem seems to be that the Control-RRC do not understand that you press the power on button. It can be caused by a few things. The program mode is not set to 5, the baudrate is not set to 57600. The cable from frontpanel to Control-RRC is not wired correct. The red jumper wires is not set correct so they make a short circuit to the the databus from the  Control panel. You can email me exported settings(html) files from both units so I can verify that  the settings are correct.

73 de mike

[dj0qn]

I suspect that you may have used a standard RJ11 telephone cable to connect the head to the RRC. That will
NOT work. It must have all wires connected. You can use what is called a "3-line telephone cord" at Radio Shack,
etc. and that will work.

73,
Mitch DJ0QN / K7DX

[K4FWJ]

Because the Auto Connect option isn't normally used it took me about a week's worth of troubleshooting to discover that selecting it would result in a reliable connection between my two boxes.  Program Mode is set to Mode 5 and the baud rate is 57600.  Although the original head connection cable ohmed out OK I still replaced it with a brand new 3-line phone cord (made no difference).  I have compared the jumpers with the pictures in the RRC manual several times.  The TS-480 is new and bought especially for this trip when my K3 suffered lightning damage just days before we left home.  Would be glad to send .html copies of my settings if I can find Mike's e-mail address.  Art

[K4FWJ]

As a side note maybe I should mention that I am hearing some sort of alert tones (lots of cw "c" characters) every time I make a change via HRD or DXLab software.  In the past, when I have used K3/K3/0-mini, I never heard these tones.  Because they are annoying I've been trying to determine their origin with no success yet.  Art 

[sm2o]

it's possible to send Personal messages via the forum , the email address is shown here http://www.remoterig.com/wp/?page_id=26.

The TS-480 sends the mode as cw when you change mode CW, USB,FM etc. maybe that's what you hear

73 de mike