If voltage is needed for the exciter a long coax line from the VFO can be tuned with a small network to provide the voltage needed at the grid of a distant buffer.
John, WA5BXO -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Saturday, February 14, 2009 7:48 PM To: [email protected] Subject: Re: [AMRadio] Broadcast transmitter rescue Todd wrote: >Don, I'd be curious to hear your thoughts on maximum connection >distance electrically for a VFO. I'm not Don but I have some thoughts: It depends a lot on the output impedance of the VFO, I'd think. If it is low-Z, say less than 100 ohms, then I'd think you could run coax quite a long way. The DDS VFO I built and use with my Gates BC-1T has a video op-amp as the output line driver so it is no problem to run a fair distance on regular coaxial cable. See http://www.wd8das.net/DDSVFO/ddsvfo.html which shows both the VFO circuit and the interface to the Gates AM rig. If you have a VFO with a high-Z output, maybe the special low-capacitance coax used for broadcast antennas on cars would help. Steve WD8DAS [email protected] http://www.wd8das.net/ ----------------------------------------------------- Radio is your best entertainment value. ----------------------------------------------------- ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: [email protected] To unsubscribe, send an email to [email protected] with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/[email protected]/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: [email protected] To unsubscribe, send an email to [email protected] with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
