Re: [Drakelist] Need a Tuner for my L4B
Michael what you're experiencing sounds like RF in the shack. In the past I've had homebrew tuners that were not robust enough to handle my 4-1000a amplifier and I experienced arcing in caps and roller inductor. However, RF in the shack is much different. Currently I run an 80 meter loop with ladder line all the back into the shack with two tuners; Ameritron ATR-30 loading the system as 450 ohm balanced on 10-80 meters and on 160 I use a homebrew tuner which I use to load the ladder line and antenna as end fed by shorting out the feedline, works like a bomb. I say all that to draw a picture that when I couple 1500 watts to the ladder line and my SWR is not tuned correctly I shut down my computer in the shack my digital mode HF radio which operates on a different antenna goes crazy and it reboots everything because of floating RF radiating from the ladderline. Once I get the SWR flat with the ATR-30 all is well and no problems and that's on all bands. If you are running coax then you can create an RF choke using coax and PVC to prevent RF from coming back into the shack. There are many tuners on the market, I happen to like the Ameritron ATR-30, I've owned many more and have MN2000 which I don't really use because it doesn't match ladder line without the outboard 4-1 balun. I also have a Swan ST-1 that's very robust but doesn't have the range to load my system on 160, the reason I chose the ATR-30. You may want to recheck your ground system and make sure everything is tied to one specific ground point in addition to rethinking your antenna tuner. 73's, WA6HYQ From: drakelist-boun...@zerobeat.net [drakelist-boun...@zerobeat.net] On Behalf Of Michael & Sue Trussell [mtruss8...@comcast.net] Sent: Thursday, March 17, 2011 9:48 AM To: drakelist@zerobeat.net Subject: [Drakelist] Need a Tuner for my L4B After many hours of frustration I have come to the conclusion I need a new tuner that will handle my L4B and my TR7. I think the VSWR shutdown function on my TR7 is really touchy on 40 meters and with my old MN2700 that I have its just making things worse. I removed the tuner and found a spot that my antenna was resonate and behold my TR7 works just fine no audio drop off. Right now I am using a resonate vertical antenna on 40 and 80 so any suggestions on tuners that will tune all the bands from 160 to 10 meters would be appreciated ! Thank you again! Michael J Trussell KA8ASN ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] MS-4 Grill
I have a complete MS4 for sale for $99 usd Bry, AF4K Sent from myTouch 4G - Reply message - From: "John Boyle" To: Subject: [Drakelist] MS-4 Grill Date: Thu, Mar 17, 2011 2:41 pm I have an MS-4 in very good condition with a singular exception - a previous owner had cut a small hole in the upper left corner and installed a spst switch. Does anyone have just a grill available for the MS-4. My speaker and cabinet are fine but I don't need the switch and would like to have an "original" case. Thank you. John Boyle, VE3PMA Portland, Ontario___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Need a Tuner for my L4B
I use a MN-2700 wih my Orion II and Alpha at 1500 watts out...works super. Also, I use the 2700 with my C line and L-4B no problems 80-10 Is there something wrong with ther tuner or aybe RFI? 73, Lee -Original Message- From: Curt Nixon To: drakelist Sent: Thu, Mar 17, 2011 1:17 pm Subject: Re: [Drakelist] Need a Tuner for my L4B Hi Michael: That sounds like perhaps a RFI issue. What does the SWR indicate with the 2700? What does the TR7 Refl indicator show? I run a TR7 here with a TR7 with and without a linear using the MN2000. THe Windom I use has real issues with rf on the feed coax above 20M and even tho the tuner says 1:1, The RF affects the TR7 and other rigs on the line as well. In my case it shows up as distorted audio and erratic ALC action. Once I put a coax choke in the feedline, problem solved. I used about 10 thurns on a 4" diameter PVC fom flat wound with the feed coax. What kind of radial /gropund sustem are you using? Is the problem only there with the 2700 in line? Does the TR7 MN2700 work ok on 40 without the L4? Curt KU8L Michael & Sue Trussell wrote: After many hours of frustration I have come to the conclusion I need a new tuner that will handle my L4B and my TR7. I think the VSWR shutdown function on my TR7 is really touchy on 40 meters and with my old MN2700 that I have its just making things worse. I removed the tuner and found a spot that my antenna was resonate and behold my TR7 works just fine no audio drop off. Right now I am using a resonate vertical antenna on 40 and 80 so any suggestions on tuners that will tune all the bands from 160 to 10 meters would be appreciated ! Thank you again! Michael J Trussell KA8ASN ___ 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
[Drakelist] L4 tuner
Why would you need a tuner for the L4? The Pi Network output is ALREADY an L network, designed to match about 30 to 100 ohms, isn't it? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Simple R4B troubleshoot
Don - If the VOM test I described isn't definitive, Richard's procedure will prove one way or the other. IF you find you need a replacement, check with hayseedhamfest.com for a drop-in replacement. 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 Richard Knoppow wrote: - Original Message - From: "Don Rasmussen" To: Sent: Thursday, March 17, 2011 10:53 AM Subject: [Drakelist] Simple R4B troubleshoot Hey guys, The fuse blew out on my R4B today. There are 2 filter caps that I am inclined to check, one is mounted underneath the power transformer, the other is the larger silver can mounted above the chassis. Can these be tested with a simple VOM? What readings to look for - shorted? Also wondering what else to test before tossing another fuse in line. The wiring attached to the NOTCH pot also seems to be disintegrating all by itself - interesting. Thanks, Don Rasmussen Carlsbad, Ca. If the caps are very bad the VOM might tell you but, in general, its not a reliable test. Electrolytics develop _parallel_ resistance, sometimes called leakage. A small amount is normal but it can become quite large, right up to being shorted. The way to tell is to use a variable power supply and a meter capable of measureing _microamps_. Probably any DMM will do it. For an electrolytic the leakage current should be pretty low, perhaps 15 uA. If the cap is bad it will be a lot more. The cap will take a while to charge and for the virtual plate to form so it should be left on the tester for a few minutes and the leakage current watched. Sometimes it will go down, which is OK but if it starts increasing toss the thing. Measuring capacitance takes a bridge or some form of capacitance meter. Bridges are good because they usually indicate _series_ resistance as well as value. Most electrolytics should have more than the marked capacitance value although modern ones are pretty close. Bad ones will measure low. High series resistance also indicates a bad cap _but_ both electrolytics and paper caps can have reasonable series resistance when the parallel resistance is low so both must be measured. It is normal for electrolytic caps to have fairly high series resistance (AKA ESR but also measured as dissipation factor). Sometimes its useful to measure the power factor by measuring the phase shift through the cap. An ideal cap will have exactly 90 degrees shift. Again, one plate of an electrolytic cap is formed chemically by action of voltage on it so measurements taken with only AC may not be adequate. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Simple R4B troubleshoot
Don - The cap under the transformer is for the 5V supply for the calibrator. Not likely to be the problem. The large silver can is _almost_ certainly the culprit. There are other possibilities of course, but ... You can check with an ohmmeter, start with the Twist-Lok cap terminal with the two white/blue wires on it. Again, this is the 'most likely' spot. Connect you meter from that terminal to chassis. The meter should show a very low resistance at first, and then start increasing. It should read 5 - 10 k ohms, depending upon many factors. If it reads in the low hundreds of ohms, probably bad. Beyond this requires either disconnecting the wiring to the various terminals or an ESR meter. If you decide to disconnect the wires, I would strongly suggest cutting them as close to the terminal as possible. The wire Drake used is extremely sensitive to heat and will melt or 'crawl back' quickly. 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 Don Rasmussen wrote: Hey guys, The fuse blew out on my R4B today. There are 2 filter caps that I am inclined to check, one is mounted underneath the power transformer, the other is the larger silver can mounted above the chassis. Can these be tested with a simple VOM? What readings to look for - shorted? Also wondering what else to test before tossing another fuse in line. The wiring attached to the NOTCH pot also seems to be disintegrating all by itself - interesting. Thanks, Don Rasmussen Carlsbad, Ca. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] MS-4 Grill
I have an MS-4 in very good condition with a singular exception - a previous owner had cut a small hole in the upper left corner and installed a spst switch. Does anyone have just a grill available for the MS-4. My speaker and cabinet are fine but I don't need the switch and would like to have an "original" case. Thank you. John Boyle, VE3PMA Portland, Ontario___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Simple R4B troubleshoot
- Original Message - From: "Don Rasmussen" To: Sent: Thursday, March 17, 2011 10:53 AM Subject: [Drakelist] Simple R4B troubleshoot Hey guys, The fuse blew out on my R4B today. There are 2 filter caps that I am inclined to check, one is mounted underneath the power transformer, the other is the larger silver can mounted above the chassis. Can these be tested with a simple VOM? What readings to look for - shorted? Also wondering what else to test before tossing another fuse in line. The wiring attached to the NOTCH pot also seems to be disintegrating all by itself - interesting. Thanks, Don Rasmussen Carlsbad, Ca. If the caps are very bad the VOM might tell you but, in general, its not a reliable test. Electrolytics develop _parallel_ resistance, sometimes called leakage. A small amount is normal but it can become quite large, right up to being shorted. The way to tell is to use a variable power supply and a meter capable of measureing _microamps_. Probably any DMM will do it. For an electrolytic the leakage current should be pretty low, perhaps 15 uA. If the cap is bad it will be a lot more. The cap will take a while to charge and for the virtual plate to form so it should be left on the tester for a few minutes and the leakage current watched. Sometimes it will go down, which is OK but if it starts increasing toss the thing. Measuring capacitance takes a bridge or some form of capacitance meter. Bridges are good because they usually indicate _series_ resistance as well as value. Most electrolytics should have more than the marked capacitance value although modern ones are pretty close. Bad ones will measure low. High series resistance also indicates a bad cap _but_ both electrolytics and paper caps can have reasonable series resistance when the parallel resistance is low so both must be measured. It is normal for electrolytic caps to have fairly high series resistance (AKA ESR but also measured as dissipation factor). Sometimes its useful to measure the power factor by measuring the phase shift through the cap. An ideal cap will have exactly 90 degrees shift. Again, one plate of an electrolytic cap is formed chemically by action of voltage on it so measurements taken with only AC may not be adequate. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Simple R4B troubleshoot
Hey guys, The fuse blew out on my R4B today. There are 2 filter caps that I am inclined to check, one is mounted underneath the power transformer, the other is the larger silver can mounted above the chassis. Can these be tested with a simple VOM? What readings to look for - shorted? Also wondering what else to test before tossing another fuse in line. The wiring attached to the NOTCH pot also seems to be disintegrating all by itself - interesting. Thanks, Don Rasmussen Carlsbad, Ca.___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Need a Tuner for my L4B
Hi Michael: That sounds like perhaps a RFI issue. What does the SWR indicate with the 2700? What does the TR7 Refl indicator show? I run a TR7 here with a TR7 with and without a linear using the MN2000. THe Windom I use has real issues with rf on the feed coax above 20M and even tho the tuner says 1:1, The RF affects the TR7 and other rigs on the line as well. In my case it shows up as distorted audio and erratic ALC action. Once I put a coax choke in the feedline, problem solved. I used about 10 thurns on a 4" diameter PVC fom flat wound with the feed coax. What kind of radial /gropund sustem are you using? Is the problem only there with the 2700 in line? Does the TR7 MN2700 work ok on 40 without the L4? Curt KU8L Michael & Sue Trussell wrote: After many hours of frustration I have come to the conclusion I need a new tuner that will handle my L4B and my TR7. I think the VSWR shutdown function on my TR7 is really touchy on 40 meters and with my old MN2700 that I have its just making things worse. I removed the tuner and found a spot that my antenna was resonate and behold my TR7 works just fine no audio drop off. Right now I am using a resonate vertical antenna on 40 and 80 so any suggestions on tuners that will tune all the bands from 160 to 10 meters would be appreciated ! Thank you again! Michael J Trussell KA8ASN ___ 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] Need a Tuner for my L4B
After many hours of frustration I have come to the conclusion I need a new tuner that will handle my L4B and my TR7. I think the VSWR shutdown function on my TR7 is really touchy on 40 meters and with my old MN2700 that I have its just making things worse. I removed the tuner and found a spot that my antenna was resonate and behold my TR7 works just fine no audio drop off. Right now I am using a resonate vertical antenna on 40 and 80 so any suggestions on tuners that will tune all the bands from 160 to 10 meters would be appreciated ! Thank you again! Michael J Trussell KA8ASN ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
