Re: [Drakelist] Drakelist Digest, Vol 35, Issue 15
Drakers, I too have the same problem and was going to do what Garey suggests, but had other "stuff" pop up (weddings, health, family, and PSK-31 bug bite), so have not tried anything yet. Waiting with baited breath to what Joe finds. I made my own cables and thery are the same total capacitance spec'ed by Drake (shorter) using the pF/foot data. Thanks Joe and others. Jim Joe Loverti wrote: When I tune up using the T-4XB PTO on 40 meters, I'm getting about 60 watts maximum. When I tune up using the R-4A PTO the power output is 95+ watts maximum. There's also about a 10 db difference in receive between the two units, the R-4A being the stronger receive of the two. I am using original Drake interconnect cables between the two units. I'd expect some difference between them, but this seems excessive. Any thoughts? WW8X Joe -- Message: 6 Date: Sat, 14 May 2011 00:01:56 -0400 From: Joe Loverti To: drakelist@zerobeat.net Subject: [Drakelist] Power output difference between T-4XB and R-4A PTO's Message-ID: Content-Type: text/plain; charset="iso-8859-1" Curt, Thanks for the answer. I'm using the cable with metal tag for the injection. I haven't tried tuning up the T-4XB without it plugged in -- I'll give it a try an see what gives. If there's no difference, that would eliminate the cable as the problem. WW8X Joe ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XC Output Varies
I had the same issue with mine. Pout would start at 140 watts at initial key down, and drift down to 90 watts. Rebuilt the AC-4 as the plate caps were "leaking" (could only see "leak" after removing tall "lytics"). Did my own rebuild with two 270 uf, 450 volt caps that I had laying around. Pout is now constant. BTW, the rebuild also fixed a sidetone issue. Look at B+ on AC-4 and see if it drifts down when you key, or just rebuild the psu for peace of mind. Jim ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Drakelist Digest, Vol 33, Issue 51
Terry, Excellent point. Use every precaution when soldering, unsoldering and grinding. Thanks Jim WA9ZBV Jim and the group: I'm the someone.. I'm also a guitar builder, and want to mention something about dust. I'm was as guilty as anyone about grinding stuff w/o even a paper mask until someone I knew was grinding abalone shell for a guitar inlay and almost had to have a lung transplant. They only did it once, too. Some dust is terribly dangerous - I don't know how solder fits in there, but it wouldn't hurt to use, at least, a paper mask. After hearing about this guy, I now use a respirator for most anything that floats in the air. Go ahead and put me in the fanatic category, but I couldn't let this go by without a small caution. 73 Terry K7WLD Wenatchee, WA -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Jim Bo Sent: Monday, 28 March, 2011 16:20 To: drakelist@zerobeat.net Subject: [Drakelist] Unsoldering Caps You can fight the solder with heat OR take the easy way and grind the solder joint with a Dremmel and cut off disk or a diamond tipped grinding bit that Dremmel also supplies. I know Iknow, some one will bring up dust and the Mayan Calendar and possible meteor...never really an issue AND the old cap pulls out with the gentlest of pulls AND there is no old solder, so the new one fits in easily AND you have a clean piece of metal to solder the new one. Or, you can risk melting wiresI have replaced caps in 4 rigs and one was with the soldering iron, solder suckers, solder wick, wire cutters and the other three were with the Dremmel. BTW, no melted wires with any of the 4 rigs. Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Unsoldering Caps
You can fight the solder with heat OR take the easy way and grind the solder joint with a Dremmel and cut off disk or a diamond tipped grinding bit that Dremmel also supplies. I know Iknow, some one will bring up dust and the Mayan Calendar and possible meteor...never really an issue AND the old cap pulls out with the gentlest of pulls AND there is no old solder, so the new one fits in easily AND you have a clean piece of metal to solder the new one. Or, you can risk melting wiresI have replaced caps in 4 rigs and one was with the soldering iron, solder suckers, solder wick, wire cutters and the other three were with the Dremmel. BTW, no melted wires with any of the 4 rigs. Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Electrolytic Removal
Dremmel tool wiht small cut off "blade" or Dremmel diamond tip "bit" with a small drill. Jim WA9zbv___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Recommended Microphone for T-4XC??
Anyone interested in selling recommended Microphone?? Thanks Jim___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XC on 160 Meters
When tuning the T-4XC on 160 meters, into a dummy load, the load control is at "zero" or maximum capacitance. I clearly do not get a peak in output power when changing the load control, the Pout continue to increase until I hit zero on the dial (max. cap). The plate control clearly has a peak at "3 on the dial". Comments?? Thanks Jim___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XC Plate Current
Is it normal for the T-4XC plate current to read 120 mA when: 1. in CW mode 2. Xmitter is keyed using mic line (no mic element connected, just foot switch). I have adjusted the bias per the manual at the mark on the meter. If not normal, any ideas as to what the issue may be? Thanks Jim___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Drake2-NT with Heathkit HG-10B won't work on 15 Meters
No output on 15 Meters with HG-10B VFO. All other bands work OK and I get output except for 15 Meters. I have done the modification where RFC1 of V1A is changed from 350 uH to 1 mH. 2-NT with HG-10B works on 80, 40, 20 and 10 Meters, won't work on 15 meters. 2-NT works on all bands when I use crystals that I have. Per Drake manual, 2-NT requires 12 Vrms on 15M, the HG-10B specs 5 Vrms output. The change in RFC1 to 1 mH was supposed to increase the output of the HG-10B per a "hints and kinks" in an old QST back in the 70's. Thoughts and comments please? Thanks Jim___ 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 between"xmtr" 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 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 ___ 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
[Drakelist] Drake 2-NT and Heathkit HG-10B
The 2-NT manual says it need 12 Volts RMS on 15 meters from a VFO to operate properly. The manual also mentions that the Heathkit HG-10B is "suitable" as an external VFO. The Heathkit manual says the output is 5v RMS open circuit. My 2-NT has less than 1 watt output on 15M and I beleive it is due to the "low" output of the Heathkit VFO (when using a 7.007 mHz xtal, it outputs full power). Any comments or experience from the members?? Thanks Jim___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Want to Buy Drake 2-C with acessories.....Please state condition and price....Thanks
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Re: [Drakelist] My Drake/Sherwood R-4C Rules my shack! (Don Jones)
IMHO, the only thing that is better than what Don describes is the R-4C as he describes BUT...use a Timewave 599ZX with a pair of noise canceling earphones (the Bose are expensive, but quite comfortable). The Timewave has a superior audio amp and I set up the filter as a bandpass with the low end at ~300 Hz and the high end at 1,500 Hz. This helps with the low end "rumble" and the high end atmosphere noise and makes the radio even more enjoyable. I rarely use the other features of the DSP filter, but on occasion, the "Random" function does help. Only on few occasions do I use the CW function of the DSP. It does help also, but for the most part, the R-4C audio into the DSP filter is "clean". I have recently aligned my R-4C and used the headphone jack with out the Timewave and again realized what a huge difference it makes. The DSP filter is not low cost, but I got it 10 years ago and it is still a viable solution. I am sure that there are lower cost filters out there, but can not attest to the audio amps on them. One of the cost drivers of the 599ZX is the ability to go to 5 kHz as the upper cut off frequency. This compares to others that have a cut off at 3 kHz or so. For amateur radio, the 3 kHz is fine, but I also use the 599ZX with my Drake R-8B for BCBDX and Beacons. Jim WA9ZBV Orange, CA -- Message: 5 Date: Sat, 5 Feb 2011 08:51:43 -0800 From: "Don Jones" To: Subject: [Drakelist] My Drake/Sherwood R-4C Rules my shack! Message-ID: <000c01cbc554$f890e040$e9b2a0c0$@net> Content-Type: text/plain; charset="us-ascii" Like some of you here, I have been working very hard to get into the log of the DX-pedition to the South Orkney Islands. My favorite band/mode has always been 40M CW. Last night I finally got my contact with them. Considering I am only running 600W to a 20M double zepp from W. WA it has been a bit of a chore. My fully loaded "Sherwood R-4C smoked my Ten Tec OMNI 6+ (which has a full load to TT filters and the INRAD CW roofing filter mod) last night. On the Drake VP8ORK was only a 529 using GUF 600Hz roofing filter and the DRAKE OEM 250Hz cw filter with no ringing filters or white noise. One the OMNI VI+ VP8ORK was only 229 due to the receiver white noise and the howling DSP noise. It is absolutely amazing to hear the difference of the two receivers. I do prefer the digital control that the "6" offers, but if you can't hear 'em you ain't going to work 'em. A trip down to Fry's electronics for a 4PDT 12V relay, a 3 pos double pole rotary wafer switch, a bud box and 6 RCA jack and 3 1/8" headphone jacks is on the agenda next so I have TR switching for the R-4C, then it is good to go for the TJ8 DX-pedition coming up next. God I Love that Sherwood R-4C. Don Jones KO7i Arlington, WA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Looking for 12.6 mHz or 12.9 mHz Xtal for T-4XC (160 Mtr)
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[Drakelist] Solved T-4XC Loss of Pwr and Side Tone issue
Thanks to ALL and everyone for help with this month old problem. The 160 meter CW contest drove me over the edge with my TS-480 on receive, and had to sort out the C line xmitter issue so I could easily use the R-4C, or be in the depths of AGC pumping for the weekend. Took a hair dryer and heated the under chassis area of V9 (Osc) and V7 (Amp) on T-4XC and initially the problem did not arise. I continued to heat to the point I was concerned it was getting to hot, and the output power went to zero and sidetone was gone. I sprayed "freeze it" on the componenets in the area of V9 and V7 and no change. I then wiggled V9 and noticed the power was intermittent. I replaced tube and had the same issue. I resoldered all solder joints on V9 and still had the same issue. I took a "pick" and "adjusted" the pins of the tube socket and the problem was solved. Occam's Razor babyjust Occam's Razor! Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XC Problem has come back............................
Well, a few hours into CQWW CWDX contest, the xmitter started to act up again. Seems to be temp related also. I lose the sidetone and the xmitter will not go into xmit when I hit the CW key. I also found that the spot function does not work. If I key the xmitter with an external foot switch, the spot function works, but the xmitter will not go into the transmit mode and the side tone does not. I was working the contest with the receiver in the "ON" position so I could get sidetone, as the keyer I have does not have a sidetone on it. Any other ideas on where to look? Garey, I need to re-read yours, but no longer have it, can you re-send? Thanks to all Jim (just recovering from a turkey coma) WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] T-4XC Oscillation and tone problem solved.
Curt, I want something around 6 volts or so DC so the fan will run slower and quite. Pin 3 and 4 is the filament for a 6AU6A tube, with pin 4 grounded at the tube socket. As soon as I disconneted the "circuit", the oscillation went away, the raspy tone on received signals on the R-4C with the injection cable connnected went away and the sidetone came up in voulme. The fan draws less than 300 mils of current. Jim - Original Message - From: "Curt Nixon" To: "Jim Bo" Cc: Sent: Saturday, November 27, 2010 7:20 AM Subject: Re: [Drakelist] T-4XC Oscillation and tone problem solved. I dont have a c version schematic but... In my fan rectifier adventures, I found that the drakes use a 12V CT filament winding..the CT is grounded ..the 12V tubes are across the whole winding...So you cannot ground one side of the rectifier/fan voltage. If you go from ground to one side of the winding, you only get 6.3V. I let the 12V fan and rectifier float..ie niether side is connected to ground. Works fine. What is different in the "c" version? Curt KU8L Jim Bo wrote: Guys, Thanks for eveyones help with the subject matter. The culprit for both of the problems was due to a circuit I added for a external fan supply. I went across the heater of V7 (Pin 3 and Pin 4) with a simple half wave rectifier circuit with 150 uF of cap for a filter. Pin 4 is at ground potential, so the diode was hanging off Pin 3. I ran this "supply voltage" to a 12 volt dc fan that was used to cool the final cage. For reasons unknown, the 'oscillation" problem AND the poor receive tone when just the injection cable connected was due to this half wave rectifier circuit. After removal of the circuit, all is back to normal, sidetone is back and solid, no oscillation and no funny T6 (Tone 6) when the injection cable was connected. Now, tomorrow morning, I will kick around 15M and 20M on CQWW DX test CW with the "new" rig. Thanks for eveyones help! Jim WA9ZBV ___ 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
[Drakelist] T-4XC Oscillation and tone problem solved.
Guys, Thanks for eveyones help with the subject matter. The culprit for both of the problems was due to a circuit I added for a external fan supply. I went across the heater of V7 (Pin 3 and Pin 4) with a simple half wave rectifier circuit with 150 uF of cap for a filter. Pin 4 is at ground potential, so the diode was hanging off Pin 3. I ran this "supply voltage" to a 12 volt dc fan that was used to cool the final cage. For reasons unknown, the 'oscillation" problem AND the poor receive tone when just the injection cable connected was due to this half wave rectifier circuit. After removal of the circuit, all is back to normal, sidetone is back and solid, no oscillation and no funny T6 (Tone 6) when the injection cable was connected. Now, tomorrow morning, I will kick around 15M and 20M on CQWW DX test CW with the "new" rig. Thanks for eveyones help! Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T4-XC "Oscillation" problem solved.........Poor tone still needs to be investigated
Guys, Thanks for all the suggestions to fix the issue. I know some of you just came out of a turkey coma to offer suggestions. I myself am about to enter a coma myself as the bird and fix'ens are almost ready. I tried the easiest recommendations and swapped the two 6UA6A's and the problem went away. Need to dig into the junk box and find a couple or order them. Did some measurements prior to entering a turky coma and results are below. Dummy load was used, Welz watt meter, and the T-4XC plate current meter and they all have their (unknown) inaccuracies. I measured plate current and output power at various positions of the "Gain" setting on the xmitter, so for what it is worth and hoping the format works): 20 meters Tune Position CW Position Gain Setting (o'clock) P out (W) Plate Current (mA) P out (W) Plate Current (mA) 9 10 120 0.4 70 10 65 240 0.4 70 11 130 320 0.4 70 12 165 350 1.5 80 1 175 360 5 100 2 175 360 20 160 3 175 360 115 310 4 175 360 200 200 5 175 360 200 200 15 Meters Tune Position CW Position Gain Setting (o'clock) P out (W) Plate Current (mA) P out (W) Plate Current (mA) 9 13 120 0.5 70 10 75 260 0.5 70 11 150 340 0.5 70 12 160 360 1 70 1 160 360 5 80 2 160 360 25 110 3 160 360 150 170 4 160 360 180 360 5 160 360 180 410 Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Drakelist Digest, Vol 29, Issue 30
Guys, Thanks for the ideas. I checked the ripple and regulation on the PSU, but will check again and post the no load and full load readings. I was not clear in the other post. I will be listening to a CW signal on the air with the R-4C, and when I turn on the xmitter with all cables attached between xmitter and rcvr, the signal from the other station that was a Tone 9 now becomes a Tone 6 (RST). If I remove the JUST the injection cable. all is well. Just connecting the injection cable causes this. All other interconnnect cables are connected. When I go to the "spot" postion, the spot signal when in cw, is also raspy with Tone 6. Now, if I turn the transcieve know to receiver, the tone is normal in the receiver. If I turn the transceiver knob to xmtr, the receive sensitivity goes down 6 S-units! All othe interconnect cables are connected, the injection line is causing these issues. Comments?? Thoughts and Happy Tnxgiving to ALL!! Jim WA9ZBV > Today's Topics: > > 1. Further info on T-4XC issue (Jim Bo) > 2. Re: Another T-4XC Question (Garey Barrell) > 3. More Info on T-4XC (Jim Bo) > > > -- > > Message: 1 > Date: Tue, 23 Nov 2010 10:14:05 -0800 > From: "Jim Bo" > To: > Subject: [Drakelist] Further info on T-4XC issue > Message-ID: <1404ce2cfd0540f0b431dc33aefd4...@jdesk> > Content-Type: text/plain; format=flowed; charset=iso-8859-1; > reply-type=original > > Hooked up my dummy load and in CW mode, > found the following: > > At full output, it takes about 2 minutes > before it goes into an "oscillation" > mode. Again, if I key the xmitter using > external switch, output power stays at > 140 watts. When I "unkey" the xmitter, > it goes into the oscillation mode. > > If I REDUCE the output power to 50 > watts, the xmitter does NOT "oscillate". > I have left the xmitter at 50 watts out > for 10 minutes and there is no issue. > As soon as I raise the output power to > greater thna 70 watts into the dummy > load, the xmitter "oscillates" between > transmitting and not transmitting. > > Thought? > > Thanks > > Jim > WA9ZBV > > > > > -- > > Message: 2 > Date: Tue, 23 Nov 2010 13:30:46 -0500 > From: Garey Barrell > To: drakelist > Subject: Re: [Drakelist] Another T-4XC Question > Message-ID: <4cec0856.2030...@mindspring.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi Jim - > > Some further information on the "oscillating" xmitter. With the key > down and in the CW position, with gain pot at max, the xmitter > "oscillates" with one second not xmitting, two seconds xmitting with > full power out. The anti vox pot setting will vary the frequency of > "oscillation". > > This sounds like a 'gassy' 6EV7/6FQ7. It MAY be C107 in the > transmitter. The DC integrated in C99 'competes' with the DC integrated > in C93 for control of the Grid of V10b. There are several large value > carbon comp resistors involved, which may have gone up in value, > disturbing the 'balance of power'. A leaky CR13 and/or CR16 can also > upset things. Leaky caps in either of these positions could be a > problem, but I have seen VERY few cap problems. >> >> Now, if I key (not the cw key) the transmitter with an external >> switch, the output power is full and of course the xmitter does not >> "oscillate" but stays in the xmit mode as expected. When I use the >> external switch to unkey the xmitter, it goes into the "oscillation >> mode again. > > CR17 / C115 generate a 'pulse' when the key is first closed to yank the > relay closed quickly to avoid the 'dropped first dot' problem. So the > relay pulls in, but relies on the voltage integrated in C99 to 'hold' it > in. >> >> I also have a question on the gain pot. It has always been >> "non-linear" in that it does not start to produce power until about >> the 1 o'clock position when in the tune positon. > > The GAIN pot is actually two sections. In TUNE position the MIC gain > section varies the SIDETONE level applied to the Grid of V9b where it is > amplified, rectified and integrated in C99. (See above). A leaky diode > at CR15, which 'keys' the sidetone for CW via control of R84/R85 vs > R101/R102 can cause a reduced level vs pot rotation. Again, high value > resistors are suspect, which will alter the balance. The GAIN control > should reach full ou
[Drakelist] T-4XC Plot Thickens
Hooked up the rcvr to the xmitter with all the patch cords and something really weird is going on. When connected together the cw signals in the R-4C become REAL raspy, about a T6 on the RST scale! Very poor. Now if I remove only the inj cable, the tone goes back to normal. I have also noted that the receiver takes MUCH longer to come back on line after you release the xmit button. It is not the relay, but rather it sounds like something is discharging with a RC time constant as the receiver gets its ears back. Comments? Tnx Jim ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] More Info on T-4XC
Well, Left T-4XC on xmit in CW position with 50 watts out into dummy load for 20 minutes and the xmitter did NOT cycle/oscillate at all. As soon as I turned up the output power to 70 watts, the xmitter cycled/oscillated between 70 watts out for 2 seconds, then zero watts out for one second with the T/R relay switching correctly. I do not have access to a tube checker, not sure if it is a tube or Thanks in advance Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Further info on T-4XC issue
Hooked up my dummy load and in CW mode, found the following: At full output, it takes about 2 minutes before it goes into an "oscillation" mode. Again, if I key the xmitter using external switch, output power stays at 140 watts. When I "unkey" the xmitter, it goes into the oscillation mode. If I REDUCE the output power to 50 watts, the xmitter does NOT "oscillate". I have left the xmitter at 50 watts out for 10 minutes and there is no issue. As soon as I raise the output power to greater thna 70 watts into the dummy load, the xmitter "oscillates" between transmitting and not transmitting. Thought? Thanks Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Another T-4XC Question
Some further information on the "oscillating" xmitter. With the key down and in the CW position, with gain pot at max, the xmitter "oscillates" with one second not xmitting, two seconds xmitting with full power out. The anti vox pot setting will vary the frequency of "oscillation". Now, if I key (not the cw key) the transmitter with an external switch, the output power is full and of course the xmitter does not "oscillate" but stays in the xmit mode as expected. When I use the external switch to unkey the xmitter, it goes into the "oscillation mode again. I also have a question on the gain pot. It has always been "non-linear" in that it does not start to produce power until about the 1 o'clock position when in the tune positon. When in the CW position and the rig keyed with CW key, there is output power (5 watts) when the gain pot is at zero. When you advance the gain pot, the output power DROPS to zero watts at about the 9 o'clock position, and then stays there until the 1 o'clock position. Is this typical? Output power is good with 140 to 150 watts watts out on 40M with 300 mils of plate current and 100 watts on 10 meters with less than 300 mils of plate current. Comments from the gang?? Thanks in advance Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T-4XC problem
Fixed the power "fade" (went from 120 watts to 80 watts within 5 seconds) by rebuilding the AC-4. All is well with the power supply, voltages are correct and ripple is good. What started the project was the fact the the xmitter, when in CW, with key down, I would get output power for two seconds. Then the transmitter would quit xmitting (heard relay click) for 1 second, then xmit for 2 seconds, then stop xmitting for 1 second. Just sat there and "oscillated from output power to no output power (relay clicking every time). The frequency of this can be changed by cranking on the anti vox pot. I cleaned relay contacts, and rotary switch contacts to no avail. I searched the web and saw someone else with a similar problem, but the thread never did reach a conclusion that the problem was fixed. Comments from the gang?? Tnx Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Drake R-4C and T-4XC frequency problem when in transceive mode
- Original Message - From: "Jim Bo" To: Sent: Friday, October 01, 2010 10:28 PM Subject: Drake R-4C and T-4XC frequency problem when in transceive mode Sorry for long post, but this will be a BIG issue for me for November SweepStakes CW. I have a problem which is noted when my R-4C is paired with the T-4XC. I tune in a CW station with the R-4C, switch a Sherwood 600 Hz roofing and 250 Hz filter and adjust the passband to clearly copy the station. As you know, with the 250 Hz filter, at 700 Hz, the signal is on the skirt of the filter and is down significantly (or even out of the passband). The frequency of the audio of the CW signal needs to be in the 500Hz (plus / minus) range to be able to hear the station. I also prefer a 500Hz "tone" when receiving CW. I then "spot" the xmitter to the same frequency such that I can hear the spot signal in the tight passband. The receiver and xmitter is on the same frequency and the other station can hear me just fine when I transmit. The problem arises when I use the R-4C PTO as the master oscillator (tranceive mode). I can tune in an external carrier generated by a Kenwood transceiver on the R-4C such that is in the passband and is solid copy. I then use a completely different receiver (Drake R8B) to receive the same carrier(using different antenna of course) such that it is in the R8B passband and at the same tone (500 Hz). I use a Timewave 599ZX with center frequency set at 500 Hz and the bandwidth knob to10 (ten) Hz for the three conditions below. Very Narrow Audio! If I then: 1. Turn T-4XC to spot mode (xmitter osc.), tune the mxitter VFO so the spot signal can clearly be heard on both the R-4C and the R8B, and through the Timewave. No Problem. 2. Transmit carrier with the T-4XC xmitter (xmitter is master ocs.), I can clearly hear the T-4XC xmitter on both the R-4C and the R8B, and through the Timewave. No Problem. 3. If I then turn the switch so the R-4C is the master oscillator (transceive mode), transmit a carrier, and listen to the R8B, the signal is no longer in the passband! Problem. I need to tune the R8B lower in frequency by 300 Hz to hear the carrier. The 300 Hz difference is significant and I do not get return calls when using the C-Line in transceive mode. If I spot the T-4XC and call the station then, I get return calls. I checked the carrier oscillator signal from both the R-4C and T-4XC and they are within 18 Hz of each other. I do recall having this issue before when I first got the C-line "back in the day" and did an adjustment to one of the rigs such that the receive and transmit frequence were the same when using the R-4C as the master oscillator (transceive mode), but do not recall what I adjusted. Any and all help / comments greatly appreciated. Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Drake R-4C and T-4XC frequency problem when in transceive mode
Sorry for long post, but this will be a BIG issue for me for November SweepStakes CW. I have a problem which is noted when my R-4C is paired with the T-4XC. I tune in a CW station with the R-4C, switch a Sherwood 600 Hz roofing and 250 Hz filter and adjust the passband to clearly copy the station. As you know, with the 250 Hz filter, at 700 Hz, the signal is on the skirt of the filter and is down significantly (or even out of the passband). The frequency of the audio of the CW signal needs to be in the 500Hz (plus / minus) range to be able to hear the station. I also prefer a 500Hz "tone" when receiving CW. I then "spot" the xmitter to the same frequency such that I can hear the spot signal in the tight passband. The receiver and xmitter is on the same frequency and the other station can hear me just fine when I transmit. The problem arises when I use the R-4C PTO as the master oscillator (tranceive mode). I can tune in an external carrier generated by a Kenwood transceiver on the R-4C such that is in the passband and is solid copy. I then use a completely different receiver (Drake R8B) to receive the same carrier(using different antenna of course) such that it is in the R8B passband and at the same tone (500 Hz). I use a Timewave 599ZX with center frequency set at 500 Hz and the bandwidth knob to10 (ten) Hz for the three conditions below. Very Narrow Audio! If I then: 1. Turn T-4XC to spot mode (xmitter osc.), tune the mxitter VFO so the spot signal can clearly be heard on both the R-4C and the R8B, and through the Timewave. No Problem. 2. Transmit carrier with the T-4XC xmitter (xmitter is master ocs.), I can clearly hear the T-4XC xmitter on both the R-4C and the R8B, and through the Timewave. No Problem. 3. If I then turn the switch so the R-4C is the master oscillator (transceive mode), transmit a carrier, and listen to the R8B, the signal is no longer in the passband! Problem. I need to tune the R8B lower in frequency by 300 Hz to hear the carrier. The 300 Hz difference is significant and I do not get return calls when using the C-Line in transceive mode. If I spot the T-4XC and call the station then, I get return calls. I checked the carrier oscillator signal from both the R-4C and T-4XC and they are within 18 Hz of each other. I do recall having this issue before when I first got the C-line "back in the day" and did an adjustment to one of the rigs such that the receive and transmit frequence were the same when using the R-4C as the master oscillator (transceive mode), but do not recall what I adjusted. Any and all help / comments greatly appreciated. Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Drake 4 C-line side tone when operating CW
I prefer a "lower than normal" pitch/freq when digging out a CW signal out of the noise or adjacent CW signals. I am using a Timewave DSP-599ZX. The tone that I "prefer" is centered at 430 Hz or so. Also, the 250 Hz I.F. crystal filter I have works best at 430Hz signal tone. Question, how do I adjust the sidetone of the T-4XC so it will fall into bandpass of the Timewave filter centered at 480Hz. Currently the side tone is at 600 Hz +/-, so when I transmit with the Timewave in line (set at 430Hz), I cannot hear the side tone or my keying. Also is there an adjustment to assure that when I am using the R-4C as the master oscillator (i.e. transceiver mode with R-4C as the controlling oscillator) I am in fact transmitting on the same frequency that I am listening to (again I tune so I hear a 430Hz CW signal using the R-4C)? Thanks in advance Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Drake 4 C-line side tone when operating CW
I prefer a "lower than normal" pitch/freq when digging out a CW signal out of the noise or adjacent CW signals. I am using a Timewave DSP-599ZX. The tone that I "prefer" is centered at 480 Hz or so. Also, the 250 Hz I.F. crystal filter I have works best at 480Hz signal tone. Question, how do I adjust the sidetone of the T-4XC so it will fall into bandpass of the Timewave filter centered at 480Hz. Currently the side tone is at 600 Hz +/-, so when I transmit with the Timewave in line (set at 480Hz), I cannot hear the side tone or my keying. Also is there an adjustment to assure that when I am using the R-4C as the master oscillator (i.e. transceiver mode with R-4C as the controlling oscillator) I am infact transmitting on the same frequency that I am listening to (again I tune so I hear a 480Hz CW signal using the R-4C)? Thanks in advance Jim WA9ZBV ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R-4C Plastic Dials
I have a R-4C tht is is need of a "kHz dial" (the one that goes 0-90"). Any ideas? Also, are the dials in a T-4XC the same and be substituted? Also, will the dials work regardless if there is one or two metal levers that are use to adjust the dials to the correct frequency? Thanks Jim ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
