[drakelist] FS-4 Repair
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Good afternoon my fellow Drake Denizens; Just when I thought it was save to go back into the water, my FS-4 developed intermittent problems. I did all the usual things like cleaning switches and checking the circuit board for solder problems and grounds, but I am afraid that one or more of the now obsolete ICs may be the culprit. I don't get a lot of bench time these days and I am interested in finding someone with more brains, experience and patience than me, to help with its repair. I would appreciate some suggestions of where I can send this thang. It's just too valuable to let it sit on the shelf as a paperweight. My best regards to all; Gene Gene McCalmont W5DDW [EMAIL PROTECTED] Argyle Texas -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net --
RE: [drakelist] L4B help
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Hello Joe; As you know, the L4B is a fairly straight forward grounded grid linear amplifier design. I've used several of these amps, including an L4 with 3-400 tubes, for many reliable years. As you suspected, the excessive grid drive is indicative of other problems and I would suspect from your description that the root cause is the lack of HV applied to the tubes, rather than the RF deck itself. The lack of HV applied to the tube plates will cause the grid to conduct excessive current. Although there are other failure modes that can present the same result, lack of HV is the most common. Please be very careful testing your amp as excessive grid will ruin your 3-500Zs. Of course, I'm sure you already know most of this. I would suggest that you check these things in order of the most simple first: 1. Do you have the HV connection to the back of the RF deck firmly fixed in place. Is this cable and connector in good shape? These components will age and although they may look good from the outside, there may be hidden problems. If all looks good, proceed to the next step. 2. Remove the top cage of the L4-PS (check your user manual for proper instructions) and inspect the "fuse resistor" (a small .82 ohm component) on the deck's top side, to determine if the resistor is OK. This resistor is mounted to an insulated post on the top of the PS and is not easily confused with the big "power dropping resistors" mounted directly to the PS transformer. Also check to confirm that the HV cable to the RF deck is properly soldered. The resistor is a common source of problems for the L4-PS and will deteriorate with age. It is designed to "self sacrifice" should the HV short in the cable or at the RF deck. If it is cracked, burnt, blistered or slightly swollen, replace it. Replacement resistors are readily available and this is an easy job. The HV cable is generally very stiff and the wire within does not take solder readily. If the PS has been worked on, it is possible that the cable has become separated from the HV supply. If everything looks good, proceed to the next step. 3. Visually inspect the diode "daughter boards" to determine if the diode stack was properly replaced and installed. It is very easy to mount these daughter boards "backwards" such that the PS HV is actually cut off on one or each cycle rather than conducting. Check the circuit diagram for your PS to determine how the cathode should be connected on each bank. It is a common failure mode to connect these daughter boards with opposite polarity. You may have to remove the two capacitor boards to adequately inspect the diode boards. If everything looks correct, proceed to the next step. 4. Visually inspect the two banks of HV capacitors for problems such as electrolyte leaks, swelling, any unusual discoloration, burn marks from excessive heat or other signs of deterioration and open leads or cold solder joints. Problems with the HV caps is the most common failure mode for the HV power supply and they are difficult to replace because axel lead HV caps of the proper size and rating are not usually available. Any observed problem means that all HV capacitors must be replaced. There is a thread on this list that addresses a new HV capacitor replacement board that would be worth looking into, however, the replacement job is not complicated and there are many threads in the list archives that explain how to do this job. If everything looks correct, proceed to the next step. 5. Walk to the fridge and open the door by grasping the handle usually located on one side of the door opposite the hinges. Pull firmly and swing the door out of the way. Inspect the contents of the fridge and find a small container, usually brown glass, narrow at the top and with a bright label affixed to the side. Remove the container from the fridge and secure the fridge door by pushing it shut. Locate an appropriate opener for the container and pry the top closure loose from the container to expose the contents within. Note: your container may be different and require a different opening procedure. Please consult the instructions specifically written for your type of container for proper procedures. Find a comfortable place to sit and enjoy the contents of the container with perhaps a nice cigar. Just maybe you will think of something that will solve your problem. Best regards; Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Joe Roth Sent: Monday, November 07, 2005 7:01 PM To: drakelist@www.zerobeat.net Subject: [drakelist] L4B help "Joe Roth" <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---
RE: [drakelist] L4-PS R12 burned - .825 ohm 2W resistor on pin 6 of cable harness
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Good evening Garey and Jason; Jason, I believe Garey to be correct in this and it's something I had not noticed in the past. I have another L-4B, left at my door in a wicker basket with a note from its previous owner, which is suffering from a blown R12. I had not been into this PS as yet, but opened it up just a few moments ago. Yup... Thar she blows (no pun intended)... A wirewound "flameproof" just as Garey had said and with the same markings (best I can tell), so I believe it was original. Interesting. However, I fear that this owner was not so lucky and it looks like one or more of the carbon bleeder resistors have cooked. I am somewhat reluctant to look further into this... before Christmas! Gary, I'm still working on my 30S-1 resolving some issues with unstable bias voltages on a 4CX1500B. I believe the fuse you referred to is almost unobtanium. Fortunately, I haven't had need of this beast! Good luck guys and keep those tubes glowing. Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 Garey Barrell <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Gene & Jason - One critique of your otherwise excellent advice. ------ On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] L4-PS R12 burned - .825 ohm 2W resistor on pin 6 of cable harness
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Hello Jason; >From your email, it appears that one of your 3-500z tubes has "bit the dust". It would be difficult to say what caused the problem, but these tubes, while robust to a fault, are not indestructible and do have a definable life cycle. It is entirely normal for the tube plates to have a dull reddish glow while the amp is keyed, however, from your description, I would say you are correct that one tube was under full load while the other was not. While color descriptions are mostly subjective, an orangey glow means the remaining tube was pulling a lot of current when observed. Depending on how long this condition existed, it too is probably exhausted. There is practically no way an average amateur can check a 3-500z unless the tube is put into service and observed. Fortunately, you had enough presence of mind to observe the tubes while switching off the power. Bravo! This is the way I would proceed: 1. You will, of course, have to open the PS to replace R12. If at all possible, replace R12 with an exact value 2w carbon resistor. If unavailable, get as close as you can using only what is available in a 2 watt configuration metal oxide composition resistor. Remember, R12 is kind of like a thermal fuse so any condition that causes excessive current draw exceeding its 2w dissipation rating, will blow the fuse. Metal oxide resistors will be slower to "give it up" than carbon, so carbon is the choice. The value of R12 is important and fortunately, it is a commonly manufactured part. 2. Observe the other PS components paying close attention to the filter capacitors, bleeder resistors and all three dropping resistors. These components may need attention as well. 3. Go to the bottom of the RF deck and observe the components and socket around the tube that was not conducting. Look for obvious problems such as swollen/cracked capacitors and resistors, burnt wire etc. At this point, I would not start wholesale replacing components. It is likely that any component failure at this point was catastrophic and should be easily discovered. 4. It is most likely that the one tube you observed had reached its end of life and will need to be replaced. When you remove the tube, mark it with a felt tip marker. What caused it to fail, having not discovered any obvious failed components on the chassis underside, will be difficult to determine. At this point, you have several options. Replace that one tube with another USED tube and get on with life, or replace BOTH 3-500z tubes with fresh examples. Although this would be a lot of work, the most optimal approach, since the amp is already down for the count, would be to freshen the PS with new capacitors and diodes, and a few other components, do a really good cleaning of the amp, service the fan motor, replace any obviously defective under chassis components at the RF deck, plunk in some new Taylor 3-500z tubes from RF Supply and Rock and Roll. You will have an awesome amp, capable of 1,500watts out, that will last you another 20+ years. Good luck and please keep me informed. Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 -Original Message- From: Jason Buchanan [mailto:[EMAIL PROTECTED] Sent: Monday, December 06, 2004 6:42 AM To: [EMAIL PROTECTED] Subject: Re: [drakelist] L4-PS R12 burned - .825 ohm 2W resistor on pin 6 of cable harness Thank you VERY much for your EXCELLENT advice - I will do some checking inside the PS today. I did notice that one tube was dark while the other was red, almost orange, when this happened. I noticed a small pop sound coming from the power supply and when I turned my head to look at the supply and start reaching for the power switch I saw that one tube appeared to be handling the entire load while the other was not doing anything. Filaments were lit on both tubes. I will take a drive by the parts store today and dig up some of those resistors. And will take OUT that tube that went dark. No idea why it would go dark and the other pick up the load - would a grid-to-filament short cause this? Thanks, Jason ------ On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] L4-PS R12 burned - .825 ohm 2W resistor on pin 6 of cable harness
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Good Morning Jason; R12 is a "protection" resistor that is the last line of defense between the L-4PS HV section and the L-4B RF deck. The resistor was meant to "blow" if there are problems at the RF deck level to protect the power supply from damage. Since R12 did let go, suspect problems "down stream" from the HV section of the L-4PS rather than the power supply itself. I've seen these go under the following conditions: 1. Overdriving the amp wherein one or both tubes pull too much current causing the resistor to let go. 2. Arching either in the tube(s) or tank circuit caused by either a defective 3-500z or improper tuning and loading of the amp. The arc momentarily draws excessive power through the HV section. 3. Arching at the antenna changeover relay caused by "hot switching". That is, a momentary "stutter" in the keying circuit causing the relay contacts to "bounce". I did this once when mindlessly letting up pressure on a Shure 444 PTT switch while speaking into the microphone. I lost both finals in the T-4Xc and R12. 4. One or more components in the RF deck have shorted to ground causing excessive HV current. Frankly, from your description, I would suspect that this is the most probable problem. I would first unplug everything, remove the bottom cover of the RF deck and do a visual inspection to see if something obvious jumps out. Checking things like bypass capacitors and looking for burnt or cracked resistors are obvious. Also check the antenna changeover relay and other components in the tank circuit for obvious damage. You might just get lucky. Let me know how you do and best regards; Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 "Jason Buchanan" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- hi all, R12 in my L4-PS burned to a crisp. Any ideas why and what I should look for as to why this happened? Amp was working fine when this happened - I powered it off as soon as I noticed the smell. 73 Jason N1SU -- On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] Tapping 115VAC from L-4PS
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- To my Esteemed Colleges: After some 25+ years of service, my L-4PS power supply for my L-4B started suffering from electronic arthritis and required a freshening. It now sports new HV capacitors, bleeder resistors, modern HV diodes with transient suppression, a "soft start" module from Harbach and other minor mechanical goodies. It now looks as good as it did originally and functions better than when new... which, except for the transformer, it is. However, I am saddened by the fact that this beauty will last only another 25 years before requiring another "freshening." Frankly, what was DRAKE thinking when they designed and built this equipment in the first place? I've got shoes older than that! So, I have considered using a fan to help expel the accumulated heat, thinking it may extend the service life of the components. And, therein lies the dilemma. The supply is wired for 220VAC. I have a 120VAC fan rated at 2100rpm and 370mA. I would like to slow the fan speed somewhat to reduce the noise, and tap the supply for the 120VAC power. I understand that my 220VAC supply side is really two 110VAC lines and that I should be able to tap off the switched side of the 220VAC (after the circuit breaker) to natural and achieve the desired 110VAC. Therefore, when the amp is switched on, the switched side energizes and the fan pulls it's required power between the switched side and natural, but this seems like risky behavior to me. When it comes to HV power supplies (anything over 12V) I start getting nervous and concerned that my sweaty palms will provide an excellent return to ground! Currently, the L-4PS is playing happily downstairs in the shack and the L-4B is delivering rated power. What is your experience with cooling the L-4PS? Or, should I, "Don't worry. Be happy"? Sincerest regards; Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 -- On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] 4-NB Noise Blanker
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang
--
Hi Al;
I'm sure you'll get lots of responses to this one, but it's cold and rainy
outside and warm here in the shack (the L-4B is a real nice space heater).
so, here are my thoughts.
The 4-NB is one of the best hardware based noise blankers I've experienced
on any radio including my new Orion. Like all hardware based blankers, it
works best on repetitive short duration pulse type noise, such as with auto
ignition or pulse type electrical line noise, say from an electrical motor.
It will not work on "white" or "pink" atmospheric noise such as you would
expect a DSP unit to handle. It will be only marginally effective on long
duration pulse noise such as with electrical static from a nearby
thunderstorm.
Another nice feature of the 4-NB is that it can be "tuned" to your
individual rig. In fact, it must be tuned to your rig to operate correctly
and tuning is an easy enough process. Insertion of the 4-NB will cause some
minor signal loss, but most owners find it negligible.
The 4-NB works best with a first IF bandwidth of at least 8K. Use of
narrower first IF filters can lead to "AGC Pumping" which will effectively
desense the receiver in the presents of strong signals. The 4-NB WILL induce
distortion products when listening to very strong signals or in the presents
of strong adjacent signals in the 8K passband.
Also, there have been reports of the cable to the receiver shorting and
wiping out your second stage IF section. Shorting is most prevalent at the
cable/plug connection rather than internal to the receiver or the 4-NB. I
should suggest that you very carefully inspect the cable/plug solder
connection to make sure that there are NO possibilities of a short as the
cable is twisted to mate the plug with the receiver. The second IF FETs are
difficult to source and replace and the dual gate FET on the first
generation of R-4Cs is "unobtanium", although a NEC near equivalent is
available.
You should note as well that there were several "versions" of the 4-NB
available. All of the versions were essentially the same electrically. The
only real difference was the board to receiver cable connection points,
length and route. The "lighter color" (a lighter shade of green )
with a shorter cable was made for the earlier generation R-4Cs without the
top shield. The darker green boards, with longer cables and different
connection point on circuit board were specific for the later R-4Cs with the
top shield. The longer cable was required to clear the shield and internal
AM filter mount. Either board will work with either generation R-4C,
however, you will find it difficult to route the shorter cable to the later
generation R-4C.
Hope all this helps.
Best regards;
Gene
W5DDW
Gene McCalmont
270 Oak Ridge Ln.
Argyle Texas 76226
n7ioh <[EMAIL PROTECTED]> made an utterence to the drakelist gang
--
I have been looking into buying the 4-NB for my R-4C. My questions, how
well does this thing work and for what kind of noise is it best suited for.
Thanks, Al, N7IOH
--
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[drakelist] Joke
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- My fellow Hams and Drake Fans; >From the moment I turn on some form of popular media in the morning, to the point I retire for the evening, I am bombarded with politically motivated "sound bites" extolling the virtues of one or the other of our political candidates or pointing out some trivial aspect of the other's personality. I subscribe to the Drake List, among others, as an escape from the noise of society and the opportunity to share with and learn from others who appreciate the old classic tube rigs. I do not feel that this forum is an appropriate outlet for politically motivated off topic post and I'm surprised that Thom, who normally runs a very tight ship, would allow this to happen, let alone continue. While I would not propose to limit your ability to speak your political mind, surely there are other forums where this would be welcomed and appreciated. I, for one, am encouraged by our lively and often contentious political climate and have a deep respect for all those candidates who ply the course toward political service. It takes a rare person to do this, wither an incumbent or a pretender. I would encourage each and every one of you to get off your duffs, support your candidate of choice and get out and vote this November. But please, respect the rest of us who may not share your political views, and use our Drake forum as it was intended. With respect; Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 ------ On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] Drake C Line Service Information
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Truly a first class effort, Gary. So, where were you when I needed this two months ago? |:-) Tell us how to order the CD. Best regards; Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Garey Barrell Sent: Sunday, September 26, 2004 11:39 AM To: Drakelist Subject: [drakelist] Drake C Line Service Information Garey Barrell <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- I have just completed a Service Part Locator for the Drake C Line. ------ On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] Inquiry on R4C es Sherwood filters
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Hello John; Your post caught my eye this afternoon, so I thought I'd share my experience with you while the Redskins get trounced by the Giants in the background. The first question you should ask yourself is "What do I intend to do with this once I'm finished?" Not all of the modifications from Sherwood are needed if you intend to operate only CW or only SSB or listen only to AM. Also, I'd ask "What is reasonable for me to spend?" A "full boat" R-4C can be an expensive proposition. I know, I've built 6 of these machines for myself and for others. They are remarkable receivers and perform very well when compared with more modern rigs. I'd also ask myself "what level of performance do I expect?" That is to say, a R-4C with the appropriate 2nd IF filters and the installation of the "GUF-1" upgrade 1st IF filter from INRAD, produces an excellent receiver with not a lot of investment. I'd suggest the 6Khz crystal filter if your operation is mostly CW/SSB. If you use your radio to listen to SW broadcast, then the 8Khz filter would be a better choice. If you have installed the 4NB, then the 8Khz filter is again your best choice. It allows the noise blanker to perform it's job better, with less pumping of the AGC. One of the most popular and biggest bang for the buck mods from Sherwood is the upgrade power supply board and the R-4C audio amplifier, AMP-4. These modifications solve two of the most annoying problems of the rig. The Sherwood web site explains the upgrades in good detail. These mods are relatively easy to perform and your cash outlay is less than $100. Everything gets progressively more complex and expensive from this point onward. I almost always replace the diode product detector in an upgraded RC-4 with the Sherwood PD-4. It gives the receiver improved headroom in the presence of strong signals. It's more difficult to install, in my opinion, but still well within the capability of most Hams. You must pay close attention to the instructions and be able to identify various components on the Drake factory circuit boards. The MIX-4 is the last upgrade I do, but only when the particular R-4C I'm working on is having problems in this area. A problematic 3rd mixer presents a noticeable hum in the audio and the typical "snap crackle pop" of a noisy 6EJ7. It is one of the more difficult mods to install. Since 6EJ7s are cheap and plentiful, I first try to find a tube that will solve the problem before resorting to the MIX-4 upgrade. Last but certainly not least are the first IF crystal filter upgrades. This is where you are going to spend a lot of money but the results are very dramatic. If operating CW exclusively, or just "a lot", the 600hz crystal filter will DRAMATICALLY improve the receiver's ability to isolate individual signals and gives the CW operator a truly superior machine. It is difficult to describe how unwanted signals just disappear when the 600Hz is switched into the IF chain. The upper and lower SSB filters dramatically improve the receivers 3rd order intercept performance with a resultant improvement in MDS in crowded band conditions. There are few receivers that offer the kind of performance these filters bring to the R-4C. The "roofing" filter approach is one of the reasons the TenTec Orion has won such acclaim for it's performance. However, installation of the filters and attendant switching circuits is not for the faint of heart. I hope this information helps out some, John. Perhaps others have differing opinions worth considering. Best regards; Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 -- On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] Inquiry on R4C es Sherwood filters
"Gene McCalmont" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Hello John; Your post caught my eye this afternoon, so I thought I'd share my experience with you while the Redskins get trounced by the Giants in the background. The first question you should ask yourself is "What do I intend to do with this once I'm finished?" Not all of the modifications from Sherwood are needed if you intend to operate only CW or only SSB or listen only to AM. Also, I'd ask "What is reasonable for me to spend?" A "full boat" R-4C can be an expensive proposition. I know, I've built 6 of these machines for myself and for others. They are remarkable receivers and perform very well when compared with more modern rigs. I'd also ask myself "what level of performance do I expect?" That is to say, a R-4C with the appropriate 2nd IF filters and the installation of the "GUF-1" upgrade 1st IF filter from INRAD, produces an excellent receiver with not a lot of investment. I'd suggest the 6Khz crystal filter if your operation is mostly CW/SSB. If you use your radio to listen to SW broadcast, then the 8Khz filter would be a better choice. If you have installed the 4NB, then the 8Khz filter is again your best choice. It allows the noise blanker to perform it's job better, with less pumping of the AGC. One of the most popular and biggest bang for the buck mods from Sherwood is the upgrade power supply board and the R-4C audio amplifier, AMP-4. These modifications solve two of the most annoying problems of the rig. The Sherwood web site explains the upgrades in good detail. These mods are relatively easy to perform and your cash outlay is less than $100. Everything gets progressively more complex and expensive from this point onward. I almost always replace the diode product detector in an upgraded RC-4 with the Sherwood PD-4. It gives the receiver improved headroom in the presence of strong signals. It's more difficult to install, in my opinion, but still well within the capability of most Hams. You must pay close attention to the instructions and be able to identify various components on the Drake factory circuit boards. The MIX-4 is the last upgrade I do, but only when the particular R-4C I'm working on is having problems in this area. A problematic 3rd mixer presents a noticeable hum in the audio and the typical "snap crackle pop" of a noisy 6EJ7. It is one of the more difficult mods to install. Since 6EJ7s are cheap and plentiful, I first try to find a tube that will solve the problem before resorting to the MIX-4 upgrade. Last but certainly not least are the first IF crystal filter upgrades. This is where you are going to spend a lot of money but the results are very dramatic. If operating CW exclusively, or just "a lot", the 600hz crystal filter will DRAMATICALLY improve the receiver's ability to isolate individual signals and gives the CW operator a truly superior machine. It is difficult to describe how unwanted signals just disappear when the 600Hz is switched into the IF chain. The upper and lower SSB filters dramatically improve the receivers 3rd order intercept performance with a resultant improvement in MDS in crowded band conditions. There are few receivers that offer the kind of performance these filters bring to the R-4C. The "roofing" filter approach is one of the reasons the TenTec Orion has won such acclaim for it's performance. However, installation of the filters and attendant switching circuits is not for the faint of heart. I hope this information helps out some, John. Perhaps others have differing opinions worth considering. Best regards; Gene W5DDW Gene McCalmont 270 Oak Ridge Ln. Argyle Texas 76226 -- On Behalf of "Gene McCalmont" <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] Drake synthesizer update.
Gene McCalmont <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- Hello Gerry; Thanks for the update on the Far Circuits "kit". I must say that I am a bit discouraged by your report. I assume that there is always some "deviation" in magazine construction projects, but as you say, had you not been in the business, you'd be dead in the water. The poor quality control on the circuit board is enough to deal with without having to interpret what parts were substituted. How does an average Ham work through this without some documentation? Thanks again for your update and please keep us informed on your progress... I for one was/am looking forward to taking up the project. Best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Gerry Sent: Sunday, June 06, 2004 12:09 PM To: [EMAIL PROTECTED] Subject: [drakelist] Drake synthesizer update. "Gerry" <[EMAIL PROTECTED]> made an utterence to the drakelist gang -- I ordered two kits from Far Circuits which arrived this week. ------ On Behalf of Gene McCalmont <[EMAIL PROTECTED]> Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] Crystal Eliminator Update?
Some weeks back, there was a very brief discussion about the Drake Crystal Eliminator article featured in the latest issue of QST. I seem to remember that several critical components were no longer available, such as the fluorescent display module and possibly the VCO. Questions: 1. Has anyone been successful in getting the parts together for this project? 2. Has anyone actually built the project? 3. Is anyone planning on building the project? If you have any experience with the Crystal Eliminator, I would appreciate hearing about your experiences. Best Regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] R-$C
Hello Evan; You bring up several, what I feel to be, very important points, but first an observation: eBay is capitalism in action, with all its "good" and "bad" ramifications for both buyers and sellers. Most of us have our war stories about eBay and I would not exclude our local Ham fests in that. Point one: The buyer must do his homework before placing a bid. Your references are worthy examples. Rule of thumb "an uninformed buyer will usually pay too much for an auction item." Of course, you could apply this rule to just about any selling situation where the seller and buyer are trying to reach a negotiated price. Point two: It is well known to savvy sellers that "auction fervor" will drive up prices. Actually, your point two is closely tied to point one. It is very easy to get tied up in a last nanosecond bidding war. Point three: Bidding on eBay is fun. In fact, it's competition that's fun... and if you win, you get a prize. It's kinda like trying to break through a pileup. Everyone wants to win. The result: someone will occasionally pay too much for an item, be it new or a vintage piece of Ham gear, and that's a shame, but it is also an excellent example of market forces at work. Now the real trick is to make sure you are not the one overpaying! Therefore, your implied conclusions are (i) be informed and know what an item is worth, (ii) set a maximum price you are willing to pay and stick with it. Before eBay, prices for and availability of vintage Ham gear was stagnant. More often than not, perfectly good vintage gear went into the Dumpster at estate sales and the tired old pieces making the Ham fest rounds were worn out. Vintage gear is more readily available today than at any time I can remember and the variety of it all is amazing. I also have a much more realistic idea of what my stuff is worth should the unspeakable happen, and my eBay savvy son has to liquidate some of the gear. Thanks for your excellent comments. Is that plastic I smell burning? I may have just found the soldering iron. 73 QRT SK; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, May 20, 2004 9:54 AM To: [EMAIL PROTECTED] Subject: Re: [drakelist] R-$C Gene, I understand your reasoning. But how about the people that pay more for a used rig than what it is currently selling new for with warranty? e.g. Yaesu FT-1500M was selling used on Upay, I mean Ebay, for upwards of $175 while it was on closeout at the dealers for $119 (I got one for $99 at Hamvention). The new Kenwood TM-271A has been selling for $185-200 on Upay, I mean Ebay, when you can get it at the dealers for $169, I got mine at Hamvention for $144. I mean, people are obviously online to do the Ebay bidding. Just typing in the model number into your search engine gives the dealer pricing and location within seconds. Yet they insist on paying more for a used rig without warranty. I was planning on buying 10-12 TM-271As and then selling them on Upay, I mean Ebay, but I just don't have the time right now. Nobody ever accused Ebay bidders as having more brains than money. Strange. 73s, Evan -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] R-$C
Good Morning from Texas; There are a number of reasons a R-4C could cost $800, and more, and they are all based on condition, options (accessories) and availability. Prices are generally set by what a willing buyer will pay and a what willing seller will accept. Although there is much "teeth gnashing" and "angst" voiced on this reflector, and others, about prices on eBay, it is a great forum for establishing "market prices" for used equipment of any type, vintage rigs included. So, consider: 1. Let's start with an Excellent to Very Good late serial R-4C, with no accessories, in good cosmetic condition, with the original manual, requiring nothing, and operating well on all bands... $325 2. Add a model appropriate and working 4NB noise blanker... $156 3. Add the AM, and three additional original crystal filters... $225 (adding new crystal filters from INRAD or Sherwood would increase the price considerably although they would perform better, IMHO) 4. Let's drop in, say, 10 band crystals at a conservative $10 each (again more if purchasing new from Sherwood or International Crystal). $100 OK, so now we have a moderately well equipped R-4C, purchased a bit at a time, that tips the scales at $806. It is a good performer and worthy of your attention. Now, lets have some fun. Let's add some stuff to update some of the marginal sections of the receiver: 1. How about a 6Khz First IF crystal filter from INRAD. $110 2. Let's upgrade the marginal power supply board and audio section with mods from Sherwood. $100 3. How about fixing than dang product detector while we're at it. $35 4. You know, the 3rd Mixer is a pain in the buttinsky, so in goes a solid state 3rd mixer stage. $59 Now, we're up to $1,110 and we have a receiver that is performing very well but still has room for improvement. How about adding additional Sherwood First IF crystal filters and a switching kit? So, in goes a 600hz CW first filter ($135), a couple of SSB filters ($199/pair) and a four filter switching including the PC boards and TO-5 relays and a custom front panel wafer switch assembly ($325) Now, we're up to $1,769 and we have, what can arguably be defended, one of the best performing receivers available... and we haven't even thought about a new DSP kit from SGC, shipping charges, bench time, interconnecting cables, starlet in Malibu (she can help install the rig), etc. If you've never heard a fully equipped R-4C on a crowded contest weekend, you owe it to yourself to find out what the fuss is all about. So, an R-4C can cost much more than $325, or $800 or... One rule of thumb worth considering: "Buy the best and most well equipped radio you can afford, that will fit your operating style/requirements, first." You will be dollars and sense (pun intended) ahead in the long run. There is nothing worse than having your classic station constantly on the bench awaiting repairs. Frankly, I'd much prefer cruising the airwaves. Now, what did I do with that dang soldering iron? Best regards; Gene P.S. These are only my opinions, for what they are worth. Others will have different and valid opinions worth consideration. W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Rocco Lardiere Sent: Thursday, May 20, 2004 6:43 AM To: [EMAIL PROTECTED]; Drake List Subject: Re: [drakelist] R-$C I saw a decent R4-C at the TRW swap meet a month ago for $325. I passed - I have two already. There were no other takers when I left. $800 is nuts, unless possibly it is new, sealed in the original box, has a crate full of extra filters, and was previously owned by some famous starlet from whom you get to pick it up at her house in Malibu. But there are always dealers out there trying to bid things up. 73, Rocco N6KN -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] Removing the RF Gain Lever R-4C
Well, it's going to take me awhile to live this one down. |:>) Obviously, the solution was rather simple, as was the brain of the guy originally asking the question. My sincerest thanks to all those who went out of their way, on a Saturday afternoon, to answer my question in a manner that preserved my sense of self-worth (LOL). It appears that, once again, it was the simplest of task that did me in. Now... where did I leave that hot soldering iron? My best regards to all; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] Removing the RF Gain Lever R-4C
Does anyone have a favorite method for removing the RF gain lever from the Drake R-4C AF/RF gain assembly? I can see no other way to facilitate removal of the front panel. I have searched the archives, the WB4HFN website and other sources finding little information. Obviously, the connection appears soldered to the RF gain pot. Surely, I'm not the only one to have asked this question. My sincerest thanks up front! Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] Disregard Sherwood wiring question
It finally occurred to me that the instructions I was reading did not apply to my installation, since I will install a filter switch that replaces the standard AGC control. Apparently the instructions were for an obsolete installation using panel-mounted toggle switches with a different board layout. It did not occur to me that obsolete instructions would be included, which did not "jive" with either the schematic drawings, board layout or pictorial views. Apparently I'm not quite as good at reading English, as written by an engineer, as I had thought. Now, Mr. Executioner, if you would just grease the blade slides like this, your blade would fall all the way and you could complete your executions. Engineers, god bless 'em, have a different way of looking at the world. Best regards and thanks for the bandwidth; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] Sherwood SSB filter board wiring question
No one said that the installation instructions from Sherwood Engineering would be easy to follow but I've run into a problem for which I can find no answer. Of course, everyone is at Dayton (but me), so I thought I'd ask the group for some help. Installing a Sherwood four filter switch kit in an R-4C --- Wiring the SSB board: (Page 3, latest version, DC Connections) #1. The instructions say to attach a 2 foot wire to the SSB filter board pad labeled BLUE and run it through the center cable-harness cutout, for a later attachment. There is no pad labeled BLUE, although I was able to figure this one out by following the schematic of the board for which there was a "Blue" connection, supplying power to the two filter-switching relays. #2. The instructions say to attach a 2 foot wire to the SSB board pad labeled +12V. There is no pad labeled +12V. The schematic diagram of the SSB filter board shows no such +12V connection and indeed shows only the connection indicated in step #1 which appears to be the same as in step #2. #3. Wire the board to a +12V source near the R-4C accessory plug. No mention of the blue wire or which wire to connect to the +12V source... although +12V would seem logical, if there were such a wire. Of course, attaching the BLUE wire to the +12V source would activate the relays locking them permanently in the closed position. No doubt, when installing the filter-switch assembly, all this will be explained, (one should hope). I'll continue to read on, but if there is someone who has some experience with this and might be able to shed some light on the installation, I would appreciate hearing from them. Best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] Cleaner for Equipment
Hello Dick; Your question is one of the more frequent questions that pops up on both this and the Collins CCA reflector and it almost always generates considerable commentary. Suggestions range from putting the gear in the dishwasher for a cycle to taking it to the carwash... although I would NOT recommend the carwash approach. You might like to search the Drake archives for some of these very informative discussions. Most of the old hands suggest using a mild biodegradable soap/detergent solution (such as Simple Green) and a bit of agitation of the contaminated surfaces with a soft brush. Follow that with an immediate GENTLE rinsing using fresh water, followed by repeated washings until the nicotine and tar residue is removed to your satisfaction. Dry the gear at low temperature (some suggest an oven at a very low temperature setting) or by placing the unit in a clean area and circulating air through and across the chassis for several hours using a common fan. Before any current is applied to the gear, it must be completely dry... COMPLETLY DRY means no moisture anywhere. There has been a lot written about the caustic nature of even the mildest soap/detergent and even Simple Green can tarnish aluminum if left in contact with the surface for any extended period of time. The rule of thumb here is to use repeated gentle washings followed by gentle rinsing along with the application of considerable patience. Then let the gear completely dry before continuing with other service activities, such as lubrication of all the switches and controls. As you mentioned, the wafer switches deserve your close attention. Smoke residue is one of the most difficult contaminants to remove but it can be successfully accomplished given some time and patience. If you get in a hurry, you are likely to damage something that previously worked. Good luck with your projects; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Richard Holder Sent: Tuesday, March 23, 2004 12:25 PM To: [EMAIL PROTECTED] Subject: [drakelist] Cleaner for Equipment I have just purchased a Drake set of rigs, R-4C, T-4XC, AC-4, MS-4, and FS-4. What would the best cleaner be? -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] S meter calibration
FYI regarding S meter calibration: Elecraft (www.elecraft.com) has produced one of the best tools I've found for measuring receiver performance and calibrating S meter readings to the 50 microvolt "standard". It is the "XG1 Receiver Test Oscillator" and it can be found at http://www.elecraft.com/mini_module_kits/mini_modules.htm. It's inexpensive (compared to other test equipment) and is an easy to build kit, which yields repeatable and accurate test results. You might want to check this out. Best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] FS-4
Hello Dan; I have had problems with my FS-4 that were similar to the symptoms you describe and the repair was rather simple, which may (or may not) mirror your situation. The FS-4 uses wafer switches similar to those found in our other classic Drake rigs. Over the years, these wafer switches build up oxidation which interferes with the switch's operation. Before I would try any advanced diagnostic/repair techniques as offered by Herbert Schulz, I suggest you clean the wafer switches with DeXoit and see if this clears up your problem. Disassembling the FS-4 is rather easy and all of the components are readily accessible. Be sure to remove the top inner shield to gain access to the wafer switches under the shield. I use DeXoit D-100 in the small dispenser bottle rather than the spray can, so that I can concentrate the cleaner on the switch contacts rather than spray down the whole assembly. If this does not solve your problem, I personally would appreciate you and Herbert posting your discovery and repair techniques to the reflector rather than go private. We can all benefit from Herbert's considerable expertise in this matter. Best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -Original Message- Does anyone have any experience with fixing a FS-4? I have one that puts out erratic freq.'s and the 0-5 does not change anything. Any ideas? Dan -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] WTB: T-4XC plate tune variable capacitor
Good afternoon to the list: I discovered this afternoon, after digging into my pristine T-4XC to find out why it wouldn't tune on 75 meters, that someone in this transmitter's history had removed a plate from the rotating portion of the plate tune air-variable capacitor. Upon close inspection, I noticed what appeared to be some minor arching that had occurred in the past. Rather than fix the problem, apparently the previous user chose instead to remove the offending plate. Actually, if one chooses to work only 40 meters and above, this was not a particularly offensive repair, as the air-variable capacitor has sufficient range to tune 40 through 10 with one less plate. However, on anything below 40 meters, there is not enough capacitance to tune the plate output circuit. So, if you have an air-variable plate tune capacitor, perhaps in a parts transmitter, and would like to sell it, I would appreciate hearing from you. My best regards to the list; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 (940) 464-4474 Office (214)-502-0322 Cell -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] R4B or R4C+mods?
Good afternoon Andy; I just received your message and had a little time on my hands so I thought I'd send some observations from my side. Of course with anything posted here or elsewhere, your mileage may vary and there are always genuinely important and differing opinions. I have and still use both an R4B and a R4C/Sherwood receiver on CW and they are both very good rigs for that purpose. IMHO, a well tuned R4C with Sherwood CW filter modifications is an outstanding performer, but it is also much more expensive than a good working R4B, which does not require further modifications to be a capable performer. If ultimate CW performance in an older style radio is your goal, and cost is no consideration, then a "Sherwoodized" late model R4C, well aligned and in proper working condition, is going to be hard to beat. However, we are talking about a substantial investment in time and money to reach this level of performance. Any well aligned R4C with it's optional CW filters can also be an excellent CW performer, without the optional Sherwood filters. A well accepted modification that really nets good results is replacing the first IF crystal filter with a 6khz 8 pole INRAD (a $125 upgrade). This greatly improves selectivity of the receiver in both SSB and CW with only a slight sacrifice in AM performance. INRAD also provides optional second IF crystal filters that are IMHO better than the original Drake units... but only slightly. Frankly, I've found that the R4B is also an excellent CW receiver and I enjoy working CW with this rig because of it's overall audio quality and it's selectable bandwidth filters. No modifications are required, save the usual alignment and general servicing of the radio. My only negative comment on the R4B is that the two 6HS6 tubes are getting very difficult to find at any reasonable price... but they don't fail all that often and can be had on the tube aftermarket. So; Ultimate Performance, price no object = a late model R4C with lots of Sherwood goodies Very good Performance, price is important = a well tuned R4C with 6Khz option and Drake filters Price an object = a really well serviced and operating R4B Of course, there are lots of other options. Best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] AC-4 Recap Capacitors?
In the midst's of a TR-4CwRIT restoration, I discovered leaking capacitors in the AC-4 power supply. Has someone already put together a capacitor substitution and cross reference list with a supplier? I understand that the double cap cans may not be available and that discrete units will have to be used, but there are a LOT of possibilities in discrete units! I've already put together a Mouser cross reference list but there may be better options. Any leads would be appreciated. I prefer using new rather than NOS. Thanks in advance! Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 (940) 464-4474 Office (214)-502-0322 Cell -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] T-4XC alignment
Hello Erling: The tuning procedure you reference in the Drake manual for the T-4XC is a bit ambiguous and is a dangerous procedure when executed incorrectly. There are high voltages present on the wafer switch which can induce an unpleasant shock and if you accidentally short a terminal, you could damage other components that may be difficult to troubleshoot. The purpose of the procedure is to detune T5 so that adjusting the injection oscillator trimmer presents a more pronounced peak when in resonance. This alignment method works very well when done properly and does provide a more accurate trimmer peak, however, you can get "close enough" without following the detune procedure by simply tuning the injection trimmer for the best peak presented. If you should choose to follow the prescribed alignment procedure, you MUST use an insulated screwdriver, securely set against the proper switch lug and hold it in place while you adjust the trimmer. When you touch the screwdriver tip to the lug, you will see a pronounced drop in plate current. Peak the trimmer for maximum then remove the screwdriver from the switch lug. Regarding setting the slugs to the right heights: I am assuming you are referring to the adjustable slugs and not to the transformer slugs present in the IF chain. I have yet to find a T-4XC that required setting these slugs and would strongly suggest that you leave them set as they came from the factory, unless they are seriously out of spec. These slugs are difficult to tune properly and do not as a general rule, require adjustment. You could do more damage than good if you attempt this part of the alignment. Of course there are many different opinions on this subject and no doubt there are others who will have a different viewpoint. As in all things, your mileage may vary. Good luck and best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] R4 and T4X injection issue, transceiving
Good Morning Ken Garey Barrell's suggestions (K4OAH) are right on target. I too have experienced the same problem as have most of us on the list. Another option you may try is to substitute your current injection cables with RG-58. Mouser sells these cables with molded RCA plugs already attached. Although the capacitance is not quite on design target, it's close. Switching to RG-58 and repeaking the set cured my problem nicely. I also use this cable combination on all of my Collins equipment with equally good results. Good luck and 73 de Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 (940) 464-4474 Office (214)-502-0322 Cell -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] KM7N Request for R4C
Apologies to the group as this is a reply to Mark's posting. Mark, I tried unsuccessfully to send you an email at your ATT.NET address only to discover that ATT WorldNet has blacklisted the out going email server at Direcway.com! If you would please respond directly to me at [EMAIL PROTECTED], I have a R4C receiver that you may be interested in. If you do not get a reply from me, you might want to call the number below. Again, my apologies to the group and thanks to the list operator for sponsoring this invaluable resource! Best regards; Gene W5DDW Gene McCalmont 270 Oakridge Road Argyle Texas 76226 (214)-502-0322 Cell -- Submissions:[EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
