A voice-keyer is a device which records standard messages , and plays them back while keying the radio in TX. - this can be very useful and handy during contests! You can build a very performant voice-keyer on basis of the VELLEMAN K8030 module, with following features:
REMARK : it seems that this VELLEMAN kit K8030 has become obsolete, a new type is available ref. MK174 - this is with IC type WinBond ISD1620D , it should work as well. See schematic here.
The VELLEMAN kit K8030 is based on a WINBOND chip
ISD1400. Download more info about this chip from my site:
This kit provides excellent audio, but is quite sensitive to presence of RF, and then will produce distortion. So you really need to take following precautions for good results:
|
|
|
|
|
|
|
|
|
|