TO minimize the effects of loading on the R-C phase shift oscillator, you can change the values of R47, R48, and R49 the resistors in the phase shift network that includes C110, C111, and C112, as follows:
120K 850 Hz 130K 790 Hz 150K 700 Hz 180K 590 Hz note: frequencies apoproximate. Of course, this does not change the deliberate, 750 Hz pulling of the carrier oscillator in CW and AM to get it to slide through the LSB filter passband. Rob - K2CU >"Gerald Reynolds" <[EMAIL PROTECTED]> wrote: > >Here is one for the 'Engineering' Drakesters. > >Can the sidetone audio PITCH be lowered when operating CW with the T4Xc? V9A >is the sidetone oscillator. The OEM pitch is about 1,000 cycles, a pitch not >too comfortable for lots of us older folks. If I could get the pitch down >between 500 and 700 cycles, it would be better for me. > >I had a bit of success by changing the value of the RC time constant in the >plate to grid feedback path (of V9A) by adding capacitance in parallel to >C110, C111, C112. By doing this, I was able to get the sidetone pitch >lowered abit, but only about 50 or 75 cycles. When I added more capacitance, >the tube became erratic and would not continue to oscillate (like it ran out >of gas). Tube internal characteristics seems to resist outside circuit >changes. > >The same thing holds true for the TR4C (V2 tube) grid to cathode ckt I >believe. >73, Gerald, KB7QQ > > > > >--- >Outgoing mail is certified Virus Free. >Checked by AVG anti-virus system (http://www.grisoft.com). >Version: 6.0.574 / Virus Database: 364 - Release Date: 1/29/04 > >---------------------------------------------------------------------- >Submissions: [EMAIL PROTECTED] >Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body >Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body >Hopelessly Lost: [EMAIL PROTECTED] - help in body of message >Brought to you courtesy of TLCHost.net http://www.tlchost.net/ >---------------------------------------------------------------------- > __________________________________________________________________ Introducing the New Netscape Internet Service. Only $9.95 a month -- Sign up today at http://isp.netscape.com/register Netscape. Just the Net You Need. New! Netscape Toolbar for Internet Explorer Search from anywhere on the Web and block those annoying pop-ups. Download now at http://channels.netscape.com/ns/search/install.jsp ---------------------------------------------------------------------- Submissions: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ ----------------------------------------------------------------------
