[Drakelist] AC-3 Ver AC-4
Well I installed a heath kit in my AC-4 and all mine does is blow the fuse when the jumper is between pins 1 and 2. I have gone over it many times. Wire for wire reds to reds yellows to yellows blues to blues etc. but it blows the 5 amp and a 6.5 amp slow blow and it blows that also. What I don't know is what capacitors to leave on the bottom there are 2 that go to ground. One from the fuse holder and one from L2 Are these needed? I did not assemble the new circuit board I bought it assembled. I know it is hard to guess without seeing and who knows what kind of goof ups a yahoo makes in wiring but anyone have an idea on where to look next ? It did not blow the fuse before the board was installed. Thanks John AG6GL ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] AC-3 Ver AC-4
john, divide and conquer! First thing to do is disconnect the secondary from the transformer to the pcb. Unsolder the wires from the 'red' wires from the transformer to the diodes. then, the 'yellow' wire that goes to the diodes. Finally, disconnect the blue wire that go from the transformer to D7 this separates the transformer from the pcb assemble. Now, check to make sure you don't have one of the loose wire contacting the chassis and when you're happy, plug in the supply and turn it on. (via shorting pins 1 and 2 together) if the fuse holds, then power down and then re-connect just one of the of the sections at a time. If you find that when you, let's say the yellow wires, blow the fuse, then you have a wiring problem on the output side, most likely a short if the fuse blows with the secondaries removed from the pcb, then you have a short someplace in the wiring that you did when connecting the wires from the transformer to the pcb this should help you, mike, wb8vge On Mar 11, 2012, at 11:36 AM, John Gartman wrote: Well I installed a heath kit in my AC-4 and all mine does is blow the fuse when the jumper is between pins 1 and 2. I have gone over it many times. Wire for wire reds to reds yellows to yellows blues to blues etc. but it blows the 5 amp and a 6.5 amp slow blow and it blows that also. What I don't know is what capacitors to leave on the bottom there are 2 that go to ground. One from the fuse holder and one from L2 Are these needed? I did not assemble the new circuit board I bought it assembled. I know it is hard to guess without seeing and who knows what kind of goof ups a yahoo makes in wiring but anyone have an idea on where to look next ? It did not blow the fuse before the board was installed. Thanks John AG6GL ___ 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] Help in identify a Mod in my R-4C
Robb - I don't recognize the HEP6050, and can't find any data on it. It's a Motorola 'replacement' (like NTE) and 'may' be an MC1496. If so, there may be a PD in Ham Radio. The original 'Sartori' PD, that I think became the Sherwood used a TL-422 originally, and later subbed with a '1496. 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 Robb Urie wrote: Howdy, While installing 4 of the Sherwood mods in my R-4C, I came across a pre-existing circuit board that turned-out to be a replacement product detector. I removed it to make way for the new PD-4, but am curious is this could be one of the early Sherwood ones or maybe a Santori version. It is on a small perf board and uses a Motorola HEP C6050G IC. I don’t have any of the HR magazines that described the DIY mods, maybe it’s time to get the CDs. I’m just wondering what it is...I’ve had this set since 1995 and have only installed the Inrad GUF-1 up to now. I've also done the LED lamp kits and they look great. For those who maybe considering doing any mods, be aware that wayward soldering irons love s-meter pots. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] FS: Unique Drake Service Supplement CDs
Here is the information that Drake left out of their manuals! Unique supplemental service information CDs available for the Drake TR-4, TR-4C/Cw/CwRIT, A, B and C Lines, 2-C / 2-NT and the 2-B receiver. High resolution color photos of the under chassis and individual PC boards of each unit, with all parts identified and keyed to a parts list make it easy to locate any component. No more trying to trace wires through bundles, etc. This information is not available elsewhere and really makes a difference in servicing these units. These CDs are NOT just scans of the original manuals that were included with the equipment when new. High resolution scans of the original manuals ARE on the CDs, along with scans of manuals for associated equipment such as the C-4, FS-4, MN2000, L-4B, W-4, etc. Samples of these pages (at reduced resolution) and purchase information are at www.k4oah.com. -- 73, Garey - K4OAH Glen Allen, VA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4B Audio Distortion
Yep - wound up being lucky this time - didn't even have to buy another tube! Someone else had mentioned the Sherwood audio amp, and this particular R-4C has that mod. Overall, it sounds good now. 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. -- From: Garey Barrell k4...@mindspring.com Sent: Saturday, March 10, 2012 11:20 AM To: Steve Wedge w1es1...@earthlink.net Cc: Mike Bryce proso...@sssnet.com; Randy WB4SPB wb4...@earthlink.net; drakelist@zerobeat.net Subject: Re: [Drakelist] R4B Audio Distortion Steve - Yes, the tube noise only seems to be a problem in the 3rd Mixer, and 'noisy' tubes can often be used in the IF with no problem. I guess it has something to do with the way the stages are biased, but I've never really investigated it. I'm lazy, I'll just select a good tube, and it usually outlasts the radio. I've had a couple (three?) guys who doubted me on this, and all three replaced every component in the AF Output stage. All three eventually ended up selecting a 6EH5! :-) It's a tough sell, cause 'I put in a NEW tube'.. :-) It's kinda like the IDLE current in a PA. If the supply voltages are there, the PA tubes WILL draw current. The only question is how much, and there you have an adjustable bias to take care of minor differences. Except in this case you don't have 'easily' adjustable bias. If you have the right cathode resistor, and the voltages are present, the tube WILL draw ~30 mA. However, (there's always a however',) when the tube gets _hot_ if the grid starts emitting electrons, or there are gas particles in the 'vacuum', the 'natural order of things' is screwed up and the tube starts drawing a little more current. Which gets a little more grid current, which gets the tube a little hotter, which 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 just wound up fixing an R-4C - and one of the things I did was to swap V4 and V6. That single exchange did more to reduce the noise in the receiver than anyting else I could have done. I did go on and convert the third mixer to cathode-feed, and that improved things a bit more, but you're on to something with respect to the audio output. OTOH, I still sit here and wonder. At audio frequencies, is everything as designed by Drake really that critical? It might be a good time to replace components to find out... Yeah - I'm a troublemaker... 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: Garey Barrell k4...@mindspring.com To: Mike Bryce proso...@sssnet.com Cc: Randy WB4SPB wb4...@earthlink.net; drakelist@zerobeat.net Sent: Friday, March 09, 2012 10:21 PM Subject: Re: [Drakelist] R4B Audio Distortion Mike - I think the problem is that 'new' tubes are 50 years old.. Even a few molecules of air a day adds up after that long. When Drake assembled the radios, the tubes were _really_ new!! The 6EH5 gets 'really' hot in normal operation, and perhaps the heat/cool cycles are harder on the metal/glass seals at the pins. Some tubes definitely are more prone to 'gas' (grid emission), the 12BA6 comes to mind. That one shows as a 'drifting' S-Meter as the tubes heat up. The 6EJ7 is prone to noise in 3rd Mixer service, probably for a similar reason. The only answer I have come up with is to keep trying tubes until you get a 'good' one. 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 Mike Bryce wrote: I wonder. when drake assembled the radios, did they go through three or fours tubes per radio to get one that worked correctly? dosen't seem logical. And although you can't argue with the fact that the subing out the tube fixed the problem, I wonder if there is something hidden down someplace in the design that causes the problem just a thought Mike, wb8vge On Mar 9, 2012, at 4:25 PM, Randy WB4SPB wrote: Altogether, I bought two 6EH5s and one 6CA5. I already had a spare 6EH5, so, considering those alone, I had to try three to get one. If I count the 6CA5 that I bought, I had to try four to get one. The 6CA5 IS very similar. Some sources do not even have the 6EH5 and refer you to 6CA5. The tube that originally manifested the problem was a 6CA5 that had been in the radio for many years before these symptoms appeared. Whether the difference in 6EH5 and 6CA5 is important here, I cannot say. I'll stick with 6EH5s in the future, while I can get them. For sources I've seen that have both, the price is the same. 73, Randy WB4SPB - Original Message - *From:*Al Al
Re: [Drakelist] Help in identify a Mod in my R-4C
Sounds like an early mod. I've seen them and mods to the C-Line were quite common back in the late '70s and early '80's. I'm thinking that it's actually harder to find an R-4C that doesn't have any changes. The folks who bought Drakes were generally more willing to go inside and soup them up. 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. From: Robb Urie Sent: Saturday, March 10, 2012 11:52 PM To: drakelist@zerobeat.net Subject: [Drakelist] Help in identify a Mod in my R-4C Howdy, While installing 4 of the Sherwood mods in my R-4C, I came across a pre-existing circuit board that turned-out to be a replacement product detector. I removed it to make way for the new PD-4, but am curious is this could be one of the early Sherwood ones or maybe a Santori version. It is on a small perf board and uses a Motorola HEP C6050G IC. I don’t have any of the HR magazines that described the DIY mods, maybe it’s time to get the CDs. I’m just wondering what it is...I’ve had this set since 1995 and have only installed the Inrad GUF-1 up to now. I've also done the LED lamp kits and they look great. For those who maybe considering doing any mods, be aware that wayward soldering irons love s-meter pots. For the folks who despise any Mods, sorry for the offense. Thanks for any info. 73, Robb N0RU Woodland Park, CO ___ 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] AC-3 Ver AC-4
Do you have a small 12 Volt transformer? Hook it up on the two 120 volt AC power plug leads with a 100 ohm resistor on series. That should allow you to do a few voltage measurements w/o blowing the fuse. everything should be 1/10th give or take what the 100ohm resistor drops. Otherwise take a ohm meter and make sure you have at lease some resistance on the primary (across the power plug). Just to make sure that the primary is not connected wrong. It should not have moved, but. easy enough to get the 120/240 sire crossed if you did disconnect them. After that, if you have not found anything, it is time to disconnect all secondaries and see if you still blow fuses. I prefer testing w/o desoldering first if possible. One last thing, look at the caps, make sure they are installed in the correct polarity. 73, Ron WD8SBB --- On Sun, 3/11/12, John Gartman johngart...@charter.net wrote: From: John Gartman johngart...@charter.net Subject: [Drakelist] AC-3 Ver AC-4 To: Drakelist@zerobeat.net Date: Sunday, March 11, 2012, 11:36 AM Well I installed a heath kit in my AC-4 and all mine does is blow the fuse when the jumper is between pins 1 and 2. I have gone over it many times. Wire for wire reds to reds yellows to yellows blues to blues etc. but it blows the 5 amp and a 6.5 amp slow blow and it blows that also. What I don't know is what capacitors to leave on the bottom there are 2 that go to ground. One from the fuse holder and one from L2 Are these needed? I did not assemble the new circuit board I bought it assembled. I know it is hard to guess without seeing and who knows what kind of goof ups a yahoo makes in wiring but anyone have an idea on where to look next ? It did not blow the fuse before the board was installed. Thanks John AG6GL -Inline Attachment Follows- ___ 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] Help in identify a Mod in my R-4C
The C6050G IC is an MC 1496. I used it myself for a product detector way back in the late 70's. I was going to make a little direct conversion receiver with it but never finished the project. Later, when I got my R4C I put the TL 442 based product detector in it and in an R4B. They worked great and the one in the R4B is still there. I completely redid the R4C with all new Sherwood mods about 5 years ago. It's still a great receiver. Steve KD2ED In a message dated 3/11/2012 7:53:10 P.M. Eastern Daylight Time, w1es1...@earthlink.net writes: Sounds like an early mod. I've seen them and mods to the C-Line were quite common back in the late '70s and early '80's. I'm thinking that it's actually harder to find an R-4C that doesn't have any changes. The folks who bought Drakes were generally more willing to go inside and soup them up. 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. From: _Robb Urie_ (mailto:ru...@mywdo.com) Sent: Saturday, March 10, 2012 11:52 PM To: _drakelist@zerobeat.net_ (mailto:drakelist@zerobeat.net) Subject: [Drakelist] Help in identify a Mod in my R-4C Howdy, While installing 4 of the Sherwood mods in my R-4C, I came across a pre-existing circuit board that turned-out to be a replacement product detector. I removed it to make way for the new PD-4, but am curious is this could be one of the early Sherwood ones or maybe a Santori version. It is on a small perf board and uses a Motorola HEP C6050G IC. I don’t have any of the HR magazines that described the DIY mods, maybe it’s time to get the CDs. I’m just wondering what it is...I’ve had this set since 1995 and have only installed the Inrad GUF-1 up to now. I've also done the LED lamp kits and they look great. For those who maybe considering doing any mods, be aware that wayward soldering irons love s-meter pots. For the folks who despise any Mods, sorry for the offense. Thanks for any info. 73, Robb N0RU Woodland Park, CO ___ 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 mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
