Re: [Drakelist] T-4XC Output Power Varies...................
Jim, If you are still having output problems w/variation between sep/rcv/xmit, PLEASE try replacing the T4XC's 6EJ7 tube...you might be surprised with the results! I had a problem vy similar to yours. PLEASE let me know if it does the trick! Regards, Ed K3JJG Unionville, PA___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Output Power Varies...................
Jim - It is normal for there to be a 'small' difference between power output and receiver sensitivity in the various TRANSCEIVE switch positions. First, the INJ cable MUST be a low capacitance coax or mic cable. Cable impedance, loss, shielding, etc. are NOT important, only the 'capacitance per foot'. The original cables were all 38 long, tip to tip. Original Drake INJ and CAR OSC Cables = 19 pF/ft = .160 o.d. (foam poly) RG-62 = 93R = 13.5 pF/ft = 0.240 o.d. RG-59 = 75R = 14.8 pF/ft = 0.242 o.d. RG-6 = 75R = 16.2 pF/ft = 0.270 o.d. RG-174= 50R = 30.8 pF/ft = 0.110 o.d. Mic Cable (Belden 8410) = Hi-Z = 33 pf/ft = 0.160 o.d. (foam poly) Mic Cable (Belden 8421) = Hi-Z = 16 pf/ft = 0.180 o.d. (foam poly) R/S Audio Patch Cable = 28 pF/ft = 0.165 o.d. (poly) The best choice is the Belden 8421 Audio cable from their Brilliance line. It looks just like the other cables, and is very flexible. The RG-62 is OK, but it is 50% larger and far less flexible. RG-62 is also prone to shorting if bent over too small a radius, and is susceptible to heat damage when soldering connectors. The best feature of RG-62 is that it is often FREE, since there have been many miles of it pulled out of old computer networks. Belden 8421 has been available by the foot from someone on the list in the recent past. The CAR OSC cable in the C-Line should be the same cable, although it isn't quite as critical. The proper cables will minimize the difference, however it may still require a touch-up of the RF TUNE and GAIN controls as well as the PRESELECTOR control in the receiver. Especially in CW, the GAIN control must be advanced further. The ALC masks this in TUNE, but the GAIN control is more critical in CW. It also helps to do the PreMixer alignment steps with the two cabled together using the correct cables. It does sound like your GAIN control is on the low side. Typically, on 40M in TUNE, you should get full output (typically 130W, limited by ALC) before 12 o'clock. CW shouldn't require more than about 1 o'clock for full output. These are two different controls on the same shaft. In TUNE one section is an AF gain control adjusting the level of a 1 kHz audio tone into the Balanced Modulator, similar to whistling into the microphone. In CW, the other section controls a DC current applied to the diodes in the Balanced Modulator to un-balance it and allow the Carrier Oscillator to come through to be amplified and mixed to generate the CW signal. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Jim Bo wrote: My T-4XC has different Pout depending on the position of the transceive switch and in the CW Mode. With transceive swith set on separate Gain is at 2:30 Plate current is 300 ma Pout is 100 watts With transceive switch set on rcvr Gain is at 2:30 Plate current is 320 ma Pout is 117 watt When transceive switch is on xmtr Gain is at 2:30 Plate current is 140 ma Pout is 19 watts When transceive switch is on xmtr Gain is at 5:00 (fully clockwise) Palte current is 320 ma Pout is 117 watts What is pecular is that Pout when seperate compared to Pout when xmtr supposedly uses the same oscillator signal for drive. I did not see anything in the manual that looks like there is an alignment step for this. Comments? Thanks Jim ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Output Power Varies...................
Garey, The cables I use for these 2 connections have a small metal clip on each end.. I think these are the ones Drake sold for that purpose?? 73, Lee -Original Message- From: Garey Barrell k4...@mindspring.com To: drakelist drakelist@zerobeat.net Sent: Tue, Mar 1, 2011 10:32 am Subject: Re: [Drakelist] T-4XC Output Power Varies... Jim - It is normal for there to be a 'small' difference between power output and receiver sensitivity in the various TRANSCEIVE switch positions. First, the INJ cable MUST be a low capacitance coax or mic cable. Cable impedance, loss, shielding, etc. are NOT important, only the 'capacitance per foot'. The original cables were all 38 long, tip to tip. Original Drake INJ and CAR OSC Cables = 19 pF/ft = .160 o.d. (foam poly) RG-62 = 93R = 13.5 pF/ft = 0.240 o.d. RG-59 = 75R = 14.8 pF/ft = 0.242 o.d. RG-6 = 75R = 16.2 pF/ft = 0.270 o.d. RG-174= 50R = 30.8 pF/ft = 0.110 o.d. Mic Cable (Belden 8410) = Hi-Z = 33 pf/ft = 0.160 o.d. (foam poly) Mic Cable (Belden 8421) = Hi-Z = 16 pf/ft = 0.180 o.d. (foam poly) R/S Audio Patch Cable = 28 pF/ft = 0.165 o.d. (poly) The best choice is the Belden 8421 Audio cable from their Brilliance line. It looks just like the other cables, and is very flexible. The RG-62 is OK, but it is 50% larger and far less flexible. RG-62 is also prone to shorting if bent over too small a radius, and is susceptible to heat damage when soldering connectors. The best feature of RG-62 is that it is often FREE, since there have been many miles of it pulled out of old computer networks. Belden 8421 has been available by the foot from someone on the list in the recent past. The CAR OSC cable in the C-Line should be the same cable, although it isn't quite as critical. The proper cables will minimize the difference, however it may still require a touch-up of the RF TUNE and GAIN controls as well as the PRESELECTOR control in the receiver. Especially in CW, the GAIN control must be advanced further. The ALC masks this in TUNE, but the GAIN control is more critical in CW. It also helps to do the PreMixer alignment steps with the two cabled together using the correct cables. It does sound like your GAIN control is on the low side. Typically, on 40M in TUNE, you should get full output (typically 130W, limited by ALC) before 12 o'clock. CW shouldn't require more than about 1 o'clock for full output. These are two different controls on the same shaft. In TUNE one section is an AF gain control adjusting the level of a 1 kHz audio tone into the Balanced Modulator, similar to whistling into the microphone. In CW, the other section controls a DC current applied to the diodes in the Balanced Modulator to un-balance it and allow the Carrier Oscillator to come through to be amplified and mixed to generate the CW signal. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Jim Bo wrote: My T-4XC has different Pout depending on the position of the transceive switch and in the CW Mode. With transceive swith set on separate Gain is at 2:30 Plate current is 300 ma Pout is 100 watts With transceive switch set on rcvr Gain is at 2:30 Plate current is 320 ma Pout is 117 watt When transceive switch is on xmtr Gain is at 2:30 Plate current is 140 ma Pout is 19 watts When transceive switch is on xmtr Gain is at 5:00 (fully clockwise) Palte current is 320 ma Pout is 117 watts What is pecular is that Pout when seperate compared to Pout when xmtr supposedly uses the same oscillator signal for drive. I did not see anything in the manual that looks like there is an alignment step for this. Comments? Thanks Jim ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Output Power Varies...................
Lee - Yes, some had a small tag, others just had a metal ring or clip. Regular cables usually had phenolic insulators in the connectors, while the low-C cables had clear or white insulators. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com kc9...@aol.com wrote: Garey, The cables I use for these 2 connections have a small metal clip on each end.. I think these are the ones Drake sold for that purpose?? 73, Lee -Original Message- From: Garey Barrell k4...@mindspring.com To: drakelist drakelist@zerobeat.net Sent: Tue, Mar 1, 2011 10:32 am Subject: Re: [Drakelist] T-4XC Output Power Varies... Jim - It is normal for there to be a 'small' difference between power output and receiver sensitivity in the various TRANSCEIVE switch positions. First, the INJ cable MUST be a low capacitance coax or mic cable. Cable impedance, loss, shielding, etc. are NOT important, only the 'capacitance per foot'. The original cables were all 38 long, tip to tip. Original Drake INJ and CAR OSC Cables = 19 pF/ft = .160 o.d. (foam poly) RG-62 = 93R = 13.5 pF/ft = 0.240 o.d. RG-59 = 75R = 14.8 pF/ft = 0.242 o.d. RG-6 = 75R = 16.2 pF/ft = 0.270 o.d. RG-174= 50R = 30.8 pF/ft = 0.110 o.d. Mic Cable (Belden 8410) = Hi-Z = 33 pf/ft = 0.160 o.d. (foam poly) Mic Cable (Belden 8421) = Hi-Z = 16 pf/ft = 0.180 o.d. (foam poly) R/S Audio Patch Cable = 28 pF/ft = 0.165 o.d. (poly) The best choice is the Belden 8421 Audio cable from their Brilliance line. It looks just like the other cables, and is very flexible. The RG-62 is OK, but it is 50% larger and far less flexible. RG-62 is also prone to shorting if bent over too small a radius, and is susceptible to heat damage when soldering connectors. The best feature of RG-62 is that it is often FREE, since there have been many miles of it pulled out of old computer networks. Belden 8421 has been available by the foot from someone on the list in the recent past. The CAR OSC cable in the C-Line should be the same cable, although it isn't quite as critical. The proper cables will minimize the difference, however it may still require a touch-up of the RF TUNE and GAIN controls as well as the PRESELECTOR control in the receiver. Especially in CW, the GAIN control must be advanced further. The ALC masks this in TUNE, but the GAIN control is more critical in CW. It also helps to do the PreMixer alignment steps with the two cabled together using the correct cables. It does sound like your GAIN control is on the low side. Typically, on 40M in TUNE, you should get full output (typically 130W, limited by ALC) before 12 o'clock. CW shouldn't require more than about 1 o'clock for full output. These are two different controls on the same shaft. In TUNE one section is an AF gain control adjusting the level of a 1 kHz audio tone into the Balanced Modulator, similar to whistling into the microphone. In CW, the other section controls a DC current applied to the diodes in the Balanced Modulator to un-balance it and allow the Carrier Oscillator to come through to be amplified and mixed to generate the CW signal. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Jim Bo wrote: My T-4XC has different Pout depending on the position of the transceive switch and in the CW Mode. With transceive swith set on separate Gain is at 2:30 Plate current is 300 ma Pout is 100 watts With transceive switch set on rcvr Gain is at 2:30 Plate current is 320 ma Pout is 117 watt When transceive switch is on xmtr Gain is at 2:30 Plate current is 140 ma Pout is 19 watts When transceive switch is on xmtr Gain is at 5:00 (fully clockwise) Palte current is 320 ma Pout is 117 watts What is pecular is that Pout when seperate compared to Pout when xmtr supposedly uses the same oscillator signal for drive. I did not see anything in the manual that looks like there is an alignment step for this. Comments? Thanks Jim ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Output Power Varies...................
Garey, Thanks for the response. I am using Belden RG-59U for the injection cable. Spec is 16.3 pf/foot and I have one foot length, so the capacitance of the cable is less than what Drake specifies. I do not have the Carrier Osc cable connected between the rigs as I understand that is for SSB only and dows not play a role in CW, but will try connecting with a 1 foot piece of Belden RG-59U (again will result in less capacitance than what Drake spec'ed). I am not sure what you mean by a touch-up of the RF TUNE and GAIN controls as well as the PRESELECTOR control in the receiver. I re-peaked both preselectors on the rcvr and xmitter and still have a big difference betweenxmtr and separate switch positions. Am I correct in saying the source of the drive for the final amplifier is same for the xmtr and separate position of the transceive switch?? Big difference between 19 watts and 100 watts. Also, what causes the need to advance the gain control so far for CW, or should I even worry about that? Is there an adjustment for that? I do not see anything in the manual that says to adjust this. Tnx Jim Message: 5 Date: Tue, 01 Mar 2011 10:30:42 -0500 From: Garey Barrell k4...@mindspring.com To: drakelist@zerobeat.net Subject: Re: [Drakelist] T-4XC Output Power Varies... Message-ID: 4d6d1122.4020...@mindspring.com Content-Type: text/plain; charset=windows-1252; format=flowed Jim - It is normal for there to be a 'small' difference between power output and receiver sensitivity in the various TRANSCEIVE switch positions. First, the INJ cable MUST be a low capacitance coax or mic cable. Cable impedance, loss, shielding, etc. are NOT important, only the 'capacitance per foot'. The original cables were all 38 long, tip to tip. Original Drake INJ and CAR OSC Cables = 19 pF/ft = .160 o.d. (foam poly) RG-62 = 93R = 13.5 pF/ft = 0.240 o.d. RG-59 = 75R = 14.8 pF/ft = 0.242 o.d. RG-6 = 75R = 16.2 pF/ft = 0.270 o.d. RG-174= 50R = 30.8 pF/ft = 0.110 o.d. Mic Cable (Belden 8410) = Hi-Z = 33 pf/ft = 0.160 o.d. (foam poly) Mic Cable (Belden 8421) = Hi-Z = 16 pf/ft = 0.180 o.d. (foam poly) R/S Audio Patch Cable = 28 pF/ft = 0.165 o.d. (poly) The best choice is the Belden 8421 Audio cable from their Brilliance line. It looks just like the other cables, and is very flexible. The RG-62 is OK, but it is 50% larger and far less flexible. RG-62 is also prone to shorting if bent over too small a radius, and is susceptible to heat damage when soldering connectors. The best feature of RG-62 is that it is often FREE, since there have been many miles of it pulled out of old computer networks. Belden 8421 has been available by the foot from someone on the list in the recent past. The CAR OSC cable in the C-Line should be the same cable, although it isn't quite as critical. The proper cables will minimize the difference, however it may still require a touch-up of the RF TUNE and GAIN controls as well as the PRESELECTOR control in the receiver. Especially in CW, the GAIN control must be advanced further. The ALC masks this in TUNE, but the GAIN control is more critical in CW. It also helps to do the PreMixer alignment steps with the two cabled together using the correct cables. It does sound like your GAIN control is on the low side. Typically, on 40M in TUNE, you should get full output (typically 130W, limited by ALC) before 12 o'clock. CW shouldn't require more than about 1 o'clock for full output. These are two different controls on the same shaft. In TUNE one section is an AF gain control adjusting the level of a 1 kHz audio tone into the Balanced Modulator, similar to whistling into the microphone. In CW, the other section controls a DC current applied to the diodes in the Balanced Modulator to un-balance it and allow the Carrier Oscillator to come through to be amplified and mixed to generate the CW signal. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XC Output Power Varies...................
My T-4XC has different Pout depending on the position of the transceive switch and in the CW Mode. With transceive swith set on separate Gain is at 2:30 Plate current is 300 ma Pout is 100 watts With transceive switch set on rcvr Gain is at 2:30 Plate current is 320 ma Pout is 117 watt When transceive switch is on xmtr Gain is at 2:30 Plate current is 140 ma Pout is 19 watts When transceive switch is on xmtr Gain is at 5:00 (fully clockwise) Palte current is 320 ma Pout is 117 watts What is pecular is that Pout when seperate compared to Pout when xmtr supposedly uses the same oscillator signal for drive. I did not see anything in the manual that looks like there is an alignment step for this. Comments? Thanks Jim___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Output Power Varies...
Two tips, First hit the switch with Deoxite. Second double check the cables you are using. I believe the INJ, CARRIER, and one other cable need to be a special low loss double shielded cable. Some of the resident experts will chime in I hope and correct any miss-information I might be spreading. Don Jones KO7i Arlington, WA Message: 8 Date: Mon, 28 Feb 2011 21:48:01 -0800 From: Jim Bo jbol...@verizon.net To: drakelist@zerobeat.net Subject: [Drakelist] T-4XC Output Power Varies... Message-ID: 689C305DD4144A1F8096AFDD0907740A@JDESK Content-Type: text/plain; charset=windows-1252 My T-4XC has different Pout depending on the position of the transceive switch and in the CW Mode. With transceive swith set on separate Gain is at 2:30 Plate current is 300 ma Pout is 100 watts With transceive switch set on rcvr Gain is at 2:30 Plate current is 320 ma Pout is 117 watt When transceive switch is on xmtr Gain is at 2:30 Plate current is 140 ma Pout is 19 watts When transceive switch is on xmtr Gain is at 5:00 (fully clockwise) Palte current is 320 ma Pout is 117 watts What is pecular is that Pout when seperate compared to Pout when xmtr supposedly uses the same oscillator signal for drive. I did not see anything in the manual that looks like there is an alignment step for this. Comments? Thanks Jim ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
