Hi Fred, The switch at C635 is a great Idea! I will make that mod the next time I visit my machine. It might not hurt if you switch the positive side of C635 to switch it to ground, rather than have it floting open. That would make the rest of the audio path very quiet, making it less likely to have noise in the audio section with out a load on the output. I prefer to take my audio as close to the detector as possible. This allows me to add the CTCSS board to the same DB9 as the controller. I slightly modified the DB9 controller interface to allow me to send the encode tone to the exciter on one of the pins formally used by one of the grounds on the NHRC2. This allows me to swap out the tone board or the controller with out effecting the other. basicly the tone board is in series with the controller. I can also "tweek" the audio response this way. Having the volume pot in line means if you use a monitor speaker and need to adjust the volume you change the repeat audio level, and something for someone else to "tweek". Also if the Audio IC dies no problem. I have only had to replace two or three in the past. This configuration allows me to make modifications to the repeater with out touching the radio. It looks like this machine will have on going mods because I would like to add several features as time goes by. 73 to All and merry Christmas and Happy Holidays Coy
--- In [email protected], "Fred Flowers" <[EMAIL PROTECTED]> wrote: > Coy, > > I use a different point to take audio from the receiver. I use P904 pin 16 RX PA. Look at the schematic for the IF & Audio board. On the Audio IC U604 pin 6 one will see RX PA out. This is used in the station intercom option. C635 is used to couple the audio to the Audio PA. You can remove that cap and not have to put a load on the speaker output. If you want RX test audio put a switch in series with the cap. Also notice that this point is after the volume control, Channel Guard filter & De-emphasis filter. Use the NHRC vol- sq board to set your level to the controller. One should have all one needs for RX audio. Make sure your controller does NOT have de- emphasis enabled. > > This method will give you control over the RX audio out & the radio will have the nice "GE" sound. > ----- Original Message ----- > From: ac0y5 > Sent: Saturday, December 13, 2003 2:26 AM > To: [email protected] > Subject: [Repeater-Builder] Re: mastrII help > > Loren, I have a repeater built out of a VHF MASTRII mobile running a > NHRC2 controller. First, your repeat audio should come from the > Volume/squelch High next, if your repeat audio is not high enough > crank up the Rx input gain. I suggest setting the master level out > pot on the controller to mid point and then adjust the remainder if > the controls to the desired level. I prefer to adjust the receive > level for 4Khz deviation in, you get 4Khz out. That way if you ever > need to make small adjustments you can use the master gain control. > as far as CAS or RUS I prefer CAS, but choose which ever you prefer. > I modified the CAS detector so it would not draw excessive current > from the circuit. Since I built my NHRC2 controller using sockets > for all chips including the opto it was easy. CAS and RUS are active > high (CAS/RUS output is about 9 volts unquenched) I used a resistor > in the input pin on the opto tied to a NPN transistor Base. The > emitter and collector are plugged into the emitter and collector > socket pins of the opto socket. > I used Molex connectors for all connections internally to the systems > board and I found connectors for the Power input. I used no part of > the cable harness. If you would like to try this, get a > squelch/Volume board from NHRC. > If you have tried what I suggested above, have you tried turning up > the deviation level on the exciter board using the pot? Use a > deviation measuring device to set your output. > 73 and good luck and let me know how it goes > AC0Y > --- In [email protected], "Loren James" > <[EMAIL PROTECTED]> wrote: > > Hi, have a UHF GE MastrII using as a repeater with a nhrc 2 > controller and > > the control head/cable w/ mic hooked up for power.. The audio > level (on the > > output) seems to be low. I have the pickup on pin 20 on J901 and > using > > CAS(pin 9 on J904) for the controller. Or should I use the RUS pin > on 904 > > board? The pots on the controller don't seem to have enough > adjustment . Any > > help ALWAYS appreciated. N2LSJ > > > > > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
