Re: [Drakelist] TR7 power supply board glitch
I think you may be onto something, Jim! Some time ago my PTO and meter dial lamps were replaced by LEDs. This is a practice frowned upon by the likes of Jeff Covelli. He objects on aesthetic grounds (not original) but also because these devices occasionally short out causing, in his words, some problems. I may have experienced one of these problems. Here's the clue: When I last powered up the rig, just before it blew, I noted that the PTO light was dead. Now, according to the schematic, it's wired in parallel with the meter lamp so it must be faulty, eh? Once I receive my replacement fuses and tantalum caps (I ordered spares just in case) and install them, I'm going to cut the LED out of the circuit and give it a whirl. If that works, I'll install my rewired power supply board again. If all is still well, I'm going to take Jeff's advice and restore the original #53 incandescent lamps. Here's hoping. Whaddya think, Jim? Many thanks for your wisdom. 73, Craig W3CRR ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] How to clean Drake knobs?
Al, A few years ago I posted a perfect solution. I first cleaned the knobs and then, using a Pentel Fine Point Correction Pen, available at office supply stores, I filled the slots with the while correction fluid, lit it dry for about an hour, then using a piece of fine edged plastic, scraped off the excess and VOILA! They still look brand new after several years. There are some other brands of fine point correction fluid dispensers that will work just as well. Shop around. Quite inexpensive. Good luck. 73, Dick KF4NS St Petersburg, FL 33714 USA Keep The Glow! Message: 5 Date: Mon, 15 Feb 2010 15:09:04 -0700 From: wenj...@gmail.com Subject: [Drakelist] How to clean Drake knobs? To: Drakelist@zerobeat.net Message-ID: 98df610d-e690-4a4c-bfab-86cc15998...@gmail.com Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed I have removed the knobs from my T-4XC and am trying to get the white stripe white again. The stripe is an off white and cleaning in hot soapy water has not helped. Has anyone found an easy way to make them white without repainting them? Thanks Al, n7ioh Payson, AZ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 power supply board glitch
Craig - For what it's worth, I agree with Jeff! :-) Even if the LED shorted, it still should NOT blow the fuse, since the limiting resistor will handle the difference in most cases. If the LEDs were of the bayonet base type that just plugged in, Jim probably had the answer. The terminals on the pilot lamp sockets turn, and then short to the chassis. Same problem in the 4 Line pieces. So the problem is NOT the LEDs themselves, the exact same problem can happen with the bulbs in there. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Craig Roberts wrote: I think you may be onto something, Jim! Some time ago my PTO and meter dial lamps were replaced by LEDs. This is a practice frowned upon by the likes of Jeff Covelli. He objects on aesthetic grounds (not original) but also because these devices occasionally short out causing, in his words, some problems. I may have experienced one of these problems. Here's the clue: When I last powered up the rig, just before it blew, I noted that the PTO light was dead. Now, according to the schematic, it's wired in parallel with the meter lamp so it must be faulty, eh? Once I receive my replacement fuses and tantalum caps (I ordered spares just in case) and install them, I'm going to cut the LED out of the circuit and give it a whirl. If that works, I'll install my rewired power supply board again. If all is still well, I'm going to take Jeff's advice and restore the original #53 incandescent lamps. Here's hoping. Whaddya think, Jim? Many thanks for your wisdom. 73, Craig W3CRR ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 power supply board glitch
Hmmm. Well, that's not promising. The LEDs are not the bayonet-type replacements. They're the Don Buska wired-in versions. Nevertheless, I'm returning to the #53 lamps and sockets. If nothing else, I like the original soft blue look better, too. Of course, I'll still have the original mystery to solve. Thanks, Garey. Craig ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 power supply board glitch
OK. Well Don's are a little different, but still a shorted LED should not blow a fuse. I assume you just soldered the leads to the old terminals? Possibly a short there. I prefer the incandescent bulb / Lee Lighting #172 film setup too. There is a reverse polarity protection diode just past the fuse, and the supply lines to the PS-7 and ACC connectors are also downstream. If It's blowing the fuse, an ohmmeter check should show the situation. You might have to reverse the ohmmeter leads to beat the polarity diode. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Craig Roberts wrote: Hmmm. Well, that's not promising. The LEDs are not the bayonet-type replacements. They're the Don Buska wired-in versions. Nevertheless, I'm returning to the #53 lamps and sockets. If nothing else, I like the original soft blue look better, too. Of course, I'll still have the original mystery to solve. Thanks, Garey. Craig ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 power supply board glitch
I don't know if anyone cares but I searched for a long time for led replacements for the #53 bulbs that would give the Drake blue color and not look purple or intense blue. Here's what I came up with and you can't tell it doesn't have the #53 bulbs in it except I don't have to remove the DR7 board every other month to replace the bulb. the bulbs I use are from SuperBrightLEDs.com part no. Warm White BA9s-WWHP6. I then added a 220 ohm 1/2 watt resistor in series with the hot lead on the bulb to dim it a little. The bulbs are a BA9 base so they go right in. If the stock blue gels are ok then the color is the same as with the #53 bulbs. If the gel is faded I use #854 Roscolene Steel Blue. If you hold this and the stock Drake blue gel up to light you can't tell any difference. Now the TR7 looks like a Drake with the proper color of blue and the LEDs should last in excess of 100,000 hours instead of 1000 hours for the #53 bulb. The LEDs also draw a lot less current and don't heat up the PTO. 73, Joe KC9LAD At 03:32 PM 2/17/2010, you wrote: OK. Well Don's are a little different, but still a shorted LED should not blow a fuse. I assume you just soldered the leads to the old terminals? Possibly a short there. I prefer the incandescent bulb / Lee Lighting #172 film setup too. There is a reverse polarity protection diode just past the fuse, and the supply lines to the PS-7 and ACC connectors are also downstream. If It's blowing the fuse, an ohmmeter check should show the situation. You might have to reverse the ohmmeter leads to beat the polarity diode. 73, Garey - K4OAH Glen Allen, VA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] UV3 parts
I'm lookiing for the black plastic cover for the frequency digits and the meter on a UV-3. Also the accessory connector, but that does not seem to be available. Anyone got either of these? 73 Thanks Terry N7BDL___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] TR-4 project with parts rig $175
Hi folks, This isn't too big a project, and includes a rough unit that has many usable pieces. 1. TR-4 s/n 28286 To the best of my knowledge it's only missing the finals and about 3 other tubes. Covers are fairly good, scratches, no dings. I've never worked on it or had it powered up. Front panel good, chassis is well tarnished. 2. TR-4 s/n 16xxx Rough shape, some parts missing, no tubes, no bottom cover. Very tarnished all over, I suspect it was submerged at one time. A few knobs are there, SB filter is there (soup-can type). Price only $175 for both, plus shipping at cost from 28560. I can email a cupla pix of each if anyone needs. 73, Al Parker, W8UT New Bern, NC www.boatanchors.org www.hammarlund.info there is nothing -absolutely nothing- half as much worth doing as simply messing about in boats. Ratty, to Mole ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 power supply board glitch
Nigel - The fuse in question is inside the TR-7, and fuses the radio, with the exception of the PA and Driver stages. So it's downstream from the crowbar, which is in the PS-7 supply. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Nigel Gunn G8IFF/W8IFF wrote: If the fuse is blowing I would suspect the over voltage crowbar is doing it. The lamps wont because the supply is current limited. On 17-Feb-10 20:32, Garey Barrell wrote: OK. Well Don's are a little different, but still a shorted LED should not blow a fuse. I assume you just soldered the leads to the old terminals? Possibly a short there. I prefer the incandescent bulb / Lee Lighting #172 film setup too. There is a reverse polarity protection diode just past the fuse, and the supply lines to the PS-7 and ACC connectors are also downstream. If It's blowing the fuse, an ohmmeter check should show the situation. You might have to reverse the ohmmeter leads to beat the polarity diode. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line TR-4/C Service Supplement CDs www.k4oah.com Craig Roberts wrote: Hmmm. Well, that's not promising. The LEDs are not the bayonet-type replacements. They're the Don Buska wired-in versions. Nevertheless, I'm returning to the #53 lamps and sockets. If nothing else, I like the original soft blue look better, too. Of course, I'll still have the original mystery to solve. Thanks, Garey. Craig ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] AC-4 / R-4C Voltage Questions
I'm in the process of getting some c-lines back to life. Befor I even started to delve into these boxes, I am making the assumption that I will need to replace electrolytics. I ordered all new single value cans of near values from Mouser. I have a few questions on voltages: AC-4 Pin #10 is showing 717VDC verse 650VDC Pin #11 is showing 292VDC verse 250VDC Pin #9 showing -60VDC - OK Pin #6/#4 showing 14VDC - OK No hum is observed with 0 load. What would cause the higher than spec voltages? Should I replace caps on general principal? R-4C Unit burnt transformer on start-up. I don't know the history of this unit. I received a replacement transformer. What would cause it to burn up? Capacitors in the power section? Thanks...jon k4wit___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] TR7 power supply board glitch
Hi Craig, On Wed, 17 Feb 2010 14:03:38 -0500, Craig Roberts wrote: I think you may be onto something, Jim! Some time ago my PTO and meter dial lamps were replaced by LEDs. This is a practice frowned upon by the likes of Jeff Covelli. He objects on aesthetic grounds (not original) but also because these devices occasionally short out causing, in his words, some problems. I respect Jeff's opinion, and I'm inclined to leave the lamps in my C-Line for similar reasons. As for the LEDs shorting out, Garey is on the money on that one. It's not the LEDs that cuase problems, they have current limit resistors. I've taken out that fuse more than once with just plain old lamps in the sockets. FOr the 7-line, I think it looks so much more modern with the cool blue LEDs. It just doesn't seem right to have digital readout, frequency synthesis, and the other advanced features of the 7-line backed by incandescent lamps. Here's hoping. Whaddya think, Jim? I hope it's that simple. Still, a short on the 13 volt rail shouldn't be that hard to track down by process of elimination. 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://radiojim(dot)exofire(dot)net http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
