Re: [Drakelist] L4B oddity
My question would now be (since you're assuming you'll have to drop a bunch of money on it anyway...) - what's the power out with it as it is, and how does it compare to how it was before you noticed the problem? Jim's right about the resistance: at 15A or thereabouts per filament @ 5V, milliohms make a difference! Steve, W1ES/4 -Original Message- From: Jim Shorney jshor...@inebraska.com Sent: Jan 3, 2012 11:26 PM To: drakelist@zerobeat.net drakelist@zerobeat.net Subject: Re: [Drakelist] L4B oddity Do you ever run with color on the plates? It's required that they get a little bit red in operation for the gettering to work. Also, just a tiny bit of extra resistance in the filament pin is all it takes to dim a tube. An ordinary Ohmmeter won't register the difference. 73 -Jim On Tue, 3 Jan 2012 22:00:06 -0600, richard radke wrote: All, Thanks to everyone who made suggestions. Solder on the pins all look ok. .5½'s on each filament. I'm guessing a grid to filament short/ leak when it gets hot. I did notice a slight bit of clouding near the top of the envelope that wasn't there before. Maybe from running the filament with way less than 5V. Thoughts ? At any rate, a replacement 3-400Z is gonna be hard to find (out of production for years) so I'll probably just get a new 3-500 to go with the one I already have. Rick W9WS -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ 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] Meter interchangeability
Folks - I see lots of TR-7 parts floating around the auction sites - including the S-meter. Are the guts of the TR-7 meter compatible with the 4-Twins? I'm just thinking ahead, in case I every have another close call where the meter doesn't survive! 73, Steve, W1ES/4 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Meter interchangeability
Nope The TR-7 is ALL new. The R-4/T-4 meters are all the same basic movement. The S-Meter is the same from the 2-A through the R-4B. The PLATE meter is the same movement, but the early scale was 0-400 mA and the later ones, (early to mid T4-XB,) changed to 0-500 mA. The TC-2 meter is 0-400 mA and the TC-6 is 0-600 mA. They all 'can' be opened and scales changed, but with a fairly high failure rate in the process. 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 Steve Wedge wrote: Folks - I see lots of TR-7 parts floating around the auction sites - including the S-meter. Are the guts of the TR-7 meter compatible with the 4-Twins? I'm just thinking ahead, in case I every have another close call where the meter doesn't survive! 73, Steve, W1ES/4 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Drake T4B
I am thinning the herd as I sort of have a Pauli Exclusion Principle at work at this QTH--too many radios and not enough space --which means two radios can be in the same place at the same time. I have a T4B that I want to find a new home for and it can be seen in rigorous detail here www.jessystems.com/T4B.html For those who may not be familiar with the T4B --it has no PTO and must either be slaved to a R (any flavor: R4, R4A, R4B or R4C). Or it can be crystal controlled and has provisions for about 10 Channels. It is operational and the only item that prevents it from being high on the grading list is some prior owner drilled a hole in the front panel which has been plugged. If there is any interest please contact me direct at radiogu...@hotmail.com My preference is no international sales and to keep shipping costs down I want to limit the shipping to the lower 48 states. My plan is to make its availability known to this list for a couple of days and then it will be listed on some of the classified/auction sites. 73's Pete N6QW ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Meter interchangeability
Thanks, Garey. I suspected as much, but wanted to be sure the movements weren't the same. That R-4B I'm working on didn't fry the meter, but there's still something out of sorts with the bridge circuit, as I can't get the meter to zero when the AGC bus is adjusted to -1.35V. Looks like I'll be checking all the other resistors that didn't look like they smoked... Steve, W1ES/4 -Original Message- From: Garey Barrell k4...@mindspring.com Sent: Jan 4, 2012 9:20 AM To: Steve Wedge w1es1...@earthlink.net Cc: drakelist@zerobeat.net drakelist@zerobeat.net Subject: Re: [Drakelist] Meter interchangeability Nope The TR-7 is ALL new. The R-4/T-4 meters are all the same basic movement. The S-Meter is the same from the 2-A through the R-4B. The PLATE meter is the same movement, but the early scale was 0-400 mA and the later ones, (early to mid T4-XB,) changed to 0-500 mA. The TC-2 meter is 0-400 mA and the TC-6 is 0-600 mA. They all 'can' be opened and scales changed, but with a fairly high failure rate in the process. 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 Steve Wedge wrote: Folks - I see lots of TR-7 parts floating around the auction sites - including the S-meter. Are the guts of the TR-7 meter compatible with the 4-Twins? I'm just thinking ahead, in case I every have another close call where the meter doesn't survive! 73, Steve, W1ES/4 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] T4B is sold
The T4B is gone. Thank you all who responded. 73's Pete N6QW___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] C-Line RTTY
I have been thinking about using my C-line for the RTTY contest this weekend. How do I set the transmit audio (gain) level. Do I set it the same as SSB where the peaks are about 150ma? I am not set up here for FSK, so its going to be a sound card affair. Any general advice for C-line RTTY? Thanks, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] S-Meter Drift and PTO Nonlinearity
I'm trying to finish this R-4B - it's one of the ones that was extensively modified, and I've brought it back - mostly. You've heard that I had to replace a fixed resistor and a pot in the S-meter bridge circuit. After getting the S METER ZERO pot to its expected range, it seems that I have to go beyond 500 ohms to zero it. Likewise the S METER SENS pot on the board underneath seems to have gone down in value to 600 ohms. Could it also be possible that the meter characteristics could have drifted over time as well? I have worked on other 4-line receivers where it seems I'm at the end of travel with the pots. Tubes are all tested good on a military tester. Now I've got a show-stopper: The PTO on this receiver is off by 6 kHz/100 kHz! I know that the PO was in there, as the can was not fully on and there was evidence of prior entry. He had also soldered the end of the coil rod (the part that sticks out) to some solder braid and had that going to a lug that was anchored to GND at one of the audio XFORMER screws. I removed that and tightened the shaft tension to kill the warble. Which caps affect the linearity, or am I setting myself up for a lot of frustration in not having Drake's fixtures and setup procedures? 73, Steve Wedge, W1ES/4 Live free or die: Death is not the worst of evils. John Stark. All my computers have my signature with various pearls of wisdom appended thereto. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] C-Line RTTY
Bob, On RTTY, peaks are the same as average. It is continuous duty. I wouldn't run the T4XC much over 50W, with tubes as expensive as they are today if it were me. You have to make your own choice, but there is a BIG difference in the duty cycles of SSB and sound card RTTY. For sure I wouldn't run much over 75W, and then with a LOT of fan moving hot air out!! I know, Garey, you ran T4XB's full out for years, HI HI. 6JB6's were 2 buck apiece at the TV shop too! 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] C-Line RTTY
Hi Bob: I have done a few RTTY contests with the T4XA and B and run them much harder than that. FSK is fixed level, tonal without the type of peaks that make metering audio difficult. I run it as hard as the tune and CW levels for plate current. Garey and Don have a lot of experience with REAL hardcore RTTY so they can verify my thoughts. (or shoot my lights out :) RTTY is fun..even with a SC program. I completed LOTW WAS for RTTY in one event. (and about 40 countries) Barefoot with the twins and a wire. Hope this helps.. Curt KU8L On 1/4/2012 6:08 PM, Robert Fish wrote: I have been thinking about using my C-line for the RTTY contest this weekend. How do I set the transmit audio (gain) level. Do I set it the same as SSB where the peaks are about 150ma? I am not set up here for FSK, so its going to be a sound card affair. Any general advice for C-line RTTY? Thanks, Bob K6GGO ___ 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] C-Line RTTY
I got a DXCC-RTTY using my T-4XC with AFSK. I agree with this. I have a fan blowing upwards above the finals. You can run 75 watts because the contest messages are short. 73, Bob WW3QB Bob, On RTTY, peaks are the same as average. It is continuous duty. I wouldn't run the T4XC much over 50W, with tubes as expensive as they are today if it were me. You have to make your own choice, but there is a BIG difference in the duty cycles of SSB and sound card RTTY. For sure I wouldn't run much over 75W, and then with a LOT of fan moving hot air out!! I know, Garey, you ran T4XB's full out for years, HI HI. 6JB6's were 2 buck apiece at the TV shop too! 73, Don, WB5HAK ___ 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] C-Line RTTY
Hi Donwelll...ya shot my lights out. :) I think you are correct if I were doing long-winded RTTY ragchews like we have done in the past. But the duty cycle is VERY short for RTTY contesting and (I'm guessing here, less than 50%. I also run a very good fan. The T4's ran very cool indeed..even set up to draw 300ma. Curt On 1/4/2012 7:43 PM, Don Cunningham wrote: Bob, On RTTY, peaks are the same as average. It is continuous duty. I wouldn't run the T4XC much over 50W, with tubes as expensive as they are today if it were me. You have to make your own choice, but there is a BIG difference in the duty cycles of SSB and sound card RTTY. For sure I wouldn't run much over 75W, and then with a LOT of fan moving hot air out!! I know, Garey, you ran T4XB's full out for years, HI HI. 6JB6's were 2 buck apiece at the TV shop too! 73, Don, WB5HAK ___ 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] R4C Sherwood mods
Yeah, but Klinger had more style... Steve Wedge, W1ES/4 I can't complain, but sometimes I still do. - Joe Walsh If the above message appears, it came from Steve's Son of Laptop! - Original Message - From: Jim Shorney jshor...@inebraska.com To: drakelist@zerobeat.net Sent: Saturday, December 31, 2011 11:58 PM Subject: Re: [Drakelist] R4C Sherwood mods On Sat, 31 Dec 2011 21:04:07 -0500 (EST), kc9...@aol.com wrote: Why invent the wheel...but as they say...go for it if it trips your trigger. By the time you buy all the parts...you won't save much. Maybe you missed the part about FUN! And the sense of accomplishment. Parts are cheap. Especially if you went to the Radar O'Rielly school of procurement. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ 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] R4C Sherwood mods
On Wed, 4 Jan 2012 21:18:49 -0500, Steve Wedge wrote: Yeah, but Klinger had more style... Ah, but Klinger stopped wearing dresses when he became company clerk. 73 -Jim (not a cross-dresser, just a modder) -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] C-Line RTTY
Bob - The C-Line does fine for RTTY. The transmitter has a jack on the back panel marked RTTY that when shorted shifts the carrier a bit to ensure that both tones (2125 - 2975 Hz 850 Hz shift,)were passed through the LSB filter unattenuated. It was originally designed when we were still using 850 shift, but is no longer of any value for today's (2125 - 2295 Hz 170 Hz shift) and should be left open. I ran multiple 4 Series transmitters on RTTY for some years, at full power and with transmissions of 30 minutes or more. You have to run them just UNDER the ALC threshold (just below where the output levels off) as you increase GAIN. PA tubes lasted a couple of years that way, with 'end of life' at 100W output max on 14.075 MHz. Obviously a small fan is a BIG help, either on top (blowing UP) or on the rear panel of the PA cage (blowing OUT). For contest type transmissions (excepting 10 minute CQs!) I wouldn't hesitate to use full power, about 340 mA. If you make long CQs, I'd back it down to about 300 mA. (~ 100W output) and the PA tubes will last 'forever'. 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 Robert Fish wrote: I have been thinking about using my C-line for the RTTY contest this weekend. How do I set the transmit audio (gain) level. Do I set it the same as SSB where the peaks are about 150ma? I am not set up here for FSK, so its going to be a sound card affair. Any general advice for C-line RTTY? Thanks, Bob K6GGO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] S-Meter Drift and PTO Nonlinearity
Steve - Don't forget that the S-Meter is a bridge that compares the current drawn by V2 and V3 with that drawn by V4 and V5. So anything that alters these two currents _differently_ can cause what you are seeing, usually 'weak' tubes. Of course ZERO drift is usually caused by gassy tubes, usually V4, 5. You know what I think of tube testers!! You can of course change R41 and/or R89 to 'balance' the bridge near the center of the pot range. Not likely that the meter has changed. You could connect it to a power supply via a series resistor and see if it follows the supply voltage linearly. It's a 3 mA movement. From what I have seen, it looks to me like the linearity adjustment is the exact value of C194. The coil is precisely wound, so linearity (especially end-to-end), would be determined in setting resonance over the 'precise' (Linear) area of the coil. Shifting C194 either way would tend to move the range along the length of the coil to find that spot. It takes some cranking from end to end to check, but If there are padder caps on C194 (usually the small tubular ones under the PC board) try removing one. The are just 'tacked' in place, and are usually less than 10 pf each (3 - 7 pF). Be sure to count exactly 10 turns with some sort of accurate dial. I bend up a piece of solid wire to register against the knob skirt. 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 Steve Wedge wrote: I'm trying to finish this R-4B - it's one of the ones that was extensively modified, and I've brought it back - mostly. You've heard that I had to replace a fixed resistor and a pot in the S-meter bridge circuit. After getting the S METER ZERO pot to its expected range, it seems that I have to go beyond 500 ohms to zero it. Likewise the S METER SENS pot on the board underneath seems to have gone down in value to 600 ohms. Could it also be possible that the meter characteristics could have drifted over time as well? I have worked on other 4-line receivers where it seems I'm at the end of travel with the pots. Tubes are all tested good on a military tester. Now I've got a show-stopper: The PTO on this receiver is off by 6 kHz/100 kHz! I know that the PO was in there, as the can was not fully on and there was evidence of prior entry. He had also soldered the end of the coil rod (the part that sticks out) to some solder braid and had that going to a lug that was anchored to GND at one of the audio XFORMER screws. I removed that and tightened the shaft tension to kill the warble. Which caps affect the linearity, or am I setting myself up for a lot of frustration in not having Drake's fixtures and setup procedures? 73, Steve Wedge, W1ES/4 Live free or die: Death is not the worst of evils. John Stark. All my computers have my signature with various pearls of wisdom appended thereto. ___ 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
