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Oil for dummy loads
I got a Heathkit Cantenna recently, sans oil.
Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
Jav -- asked many times before -- for the answers go to Groups Google.com
http://groups.google.com/ Search for Oil For Cantenna or Oil For Dummy Load Mineral Oil works well for me. "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
"Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms I would NOT use motor oil. I would suggest mineral oil if you can't find transformer oil (used to have PCBs in it, but I believe they've been banned). Carl - wk3c |
Your local power company has it. Generally at their transformer maintenance
shop.... I got 2 gallons which will last me a lifetime free. They buy it by the rail tanker and said the cost to figure out what to charge for 1 - 2 gals was more then it was worth grin. They use the stuff in transformers. It's highly refined mineral oil and has anti oxidation additives etc. so it's not "just" mineral oil. There are several makers and brand names but the stuff I got is made by Shell and is called Shell Diala (apparently named ala dialectric oil). Mike, W9WIS |
This came up about a month ago. Several people mentioned that they are using
automatic transmission fluid. Tam/WB2TT "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
DO NOT USE MOTOR OIL. DO NOT USE TRANSFORMER OIL.
Use MINERAL OIL ONLY. It is fine for 'normal' Amateur radio powerlevels. However it WILL cook a bit at 1300 watts if you keep it up a while. You can get it at a standard drug store. Dan/W4NTI "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
On 08 Aug 2003 13:58:57 -0700, Javier Henderson
wrote: I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms I used drug store mineral oil in my Cantenna. Worked fine for 100 watts, but kind of expensive, buying it by the pint :-) MFJ sells a gallon of transformer oil, by itself (they also sell their version of the Cantenna). Check their website. Bob k5qwg |
"Keyboard In The Wilderness" wrote in message news:fjUYa.31252$ff.5358@fed1read01...
Jav -- asked many times before -- for the answers go to Groups Google.com http://groups.google.com/ I don,t fully understand why motor oil should not be used in a dummy load! I need to make one so I can calibrate one of my instruments. I intend to use one of the uptodate gallon paint cans that has a PTFE liner and solder the lid on. Since we now have the means to use low wattage signals for tuning up purposes there is obviously no reason to store it in the shack . So what really is the problem with using available oil instead of emulating the aproach of industrial transformers or regurgitating old thoughts ? Art Search for Oil For Cantenna or Oil For Dummy Load Mineral Oil works well for me. "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
Mineral oil from the drugstore works just fine, is easy to get, and is
inexpensive. BUT keep the dummy load in a small plastic pail/pan. When it overheats, it vents to the top and then down the sides. |
Figured yiu have enough advice on the oil so here is my story.
I had a cantenna that set beneath my bech for about seven years. One day I sat down at the bench and felt oil all over the floor. The bottom of the can had rusted out. After procurring a new paint can I tinned the outside of the can with solder. New can has lasted 18 years so far without any sign of rust. However it has never been on a bare concrete floor either. "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
Way back in the 1970's I visited the National Physical Laboratory (NPL) at
Teddington, West London. I was priviledged to see, but not to touch, the National Standards of the Ohm and of the Volt. There were a number of 4-terminal resistors submerged in a temperature-controlled oil bath. There was about a dozen Western Cells with connecting wires submerged in another temperature-controlled oil bath. There were small fans in the oil to ensure a very slow circulation. I asked my guide, the physicist responsible for maintaining these vital standards of measurement on which the Commercial, Industrial, Engineering, Scientific life of the Nation is supported, what special sort of oil was used in the baths? He said it was the same stuff, without the perfume, as young men used for hair oil and came from a tree in Malaya. ---- Reg, G4FGQ |
Jav...
I've had one for about 30 years, run everything from an 80m Kallyfornia Kilowatt to a 1 watt aircraft transmitter into nothing more than K-mart automatic transmission fluid. Excellent results. BTW, read your local paper when it lists the 150+ people running for governor. Expecially read the last names beginning with W {;-) Jim Javier Henderson shared these priceless pearls of wisdom: -I got a Heathkit Cantenna recently, sans oil. - -Where do I find transformer oil? The few industrial suppliers in my -area (Monterey, CA) want to sell me drums of the stuff. I only need -a gallon... - -Is motor oil OK to use? - -73, --jav w6vms Jim Weir, VP Eng. RST Eng. WX6RST A&P, CFI, and other good alphabet soup |
Well it would seem that the 'don't use motor oil' comment
which has been passed on by mouth to mouth over the decades doesn't seem to stand up to scruteny. Yes, the question is raised so many times over the years and the same old stories pop up, but without any substantiation such that it just appears to be gossip. One statement mentions attack on resisters, where's the proof, If it is true then it surely can be easily overcome. Hopefully this time, one of the many posters over the years on this subject will make observations that are relevant to the present day instead of waiting for a book. Art "Keyboard In The Wilderness" wrote in message news:4q8Za.31351$ff.14186@fed1read01... From the Google Group Search Engine: For what it is worth The Handbook (at least my 1990 edition) has some information on this subject. In the Station Accessories chapter there are plans to build a couple of Cantenna type dummy loads. They mention an oil sold by Texaco (if I remember correctly) for turbine lubrication that is, according to the author, the same oil as is used in transformers. They quote the exact product designation. Apparently, it's sold in minimum 5 gallon quantities and I think it's about $5 per gallon. If anyone's interested, let me know and I'll look up the information and pass it along. It's supposed to be PCB-free, also. The article also cautions against using motor oil for various reasons, among which is that it attacks the resistor (actually, I think it's the additives that cause the problem). "Art Unwin KB9MZ" wrote in message m... "Keyboard In The Wilderness" wrote in message news:fjUYa.31252$ff.5358@fed1read01... Jav -- asked many times before -- for the answers go to Groups Google.com http://groups.google.com/ I don,t fully understand why motor oil should not be used in a dummy load! I need to make one so I can calibrate one of my instruments. I intend to use one of the uptodate gallon paint cans that has a PTFE liner and solder the lid on. Since we now have the means to use low wattage signals for tuning up purposes there is obviously no reason to store it in the shack . So what really is the problem with using available oil instead of emulating the aproach of industrial transformers or regurgitating old thoughts ? Art Search for Oil For Cantenna or Oil For Dummy Load Mineral Oil works well for me. "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
Jim Weir writes:
I've had one for about 30 years, run everything from an 80m Kallyfornia Kilowatt to a 1 watt aircraft transmitter into nothing more than K-mart automatic transmission fluid. Excellent results. Excellent. I -may- have to make-do with WalMart's brand, but we'll see. BTW, read your local paper when it lists the 150+ people running for governor. Expecially read the last names beginning with W {;-) I already sent in my dollar. Go Jim! -jav |
Russ,
The point I am making is that some comments are repeated so many times they take a life of their own Think about it, the resistors of old are a far cry from the carbon resistors of today which are not as porous, if it is a worry then coat it with epoxy ! Then there is the "rust" question, the paint cans of today have a teflon liner ! Even the latest ham data states that motor oil CAN be used ( no, it will not explode !) but raise a question of "life", possibly a suggestive comment that you change the oil every 5000 qso's. Certainly industry gives a good guide as to what is the best to use for their circumstances but it doesn't rule out every thing else for all time, and this includes motor oil of which there are many types. Regards Art Russ wrote in message . .. On 10 Aug 2003 08:19:18 -0700, (Art Unwin KB9MZ) wrote: Well it would seem that the 'don't use motor oil' comment which has been passed on by mouth to mouth over the decades doesn't seem to stand up to scruteny. Yes, the question is raised so many times over the years and the same old stories pop up, but without any substantiation such that it just appears to be gossip. One statement mentions attack on resisters, where's the proof, If it is true then it surely can be easily overcome. Hopefully this time, one of the many posters over the years on this subject will make observations that are relevant to the present day instead of waiting for a book. Art Well Art, the detergents in modern motor oils are specifically formulated to dissolve carbon deposits and sludge (largely made up of carbon) and keep in in suspension. I'm pretty sure that the resistor in my Cantenna is carbon. Transformer oil is formulated to have a high dieletric strength. Mineral oil is relatively pure, lightweight petrolatum (like liquid Vaseline(r)) and has a pretty high dieletric strength just because of low impurities. Motor oil? I don't know. ATF? I don't know about that either. What I do know is that the designers of my dummy load specify either transformer oil or mineral oil. That's good enough for me. I'll mosey on down to the transformer shop of the local electric utility and buy the folks there a round of coffee in the morning or over to the veterinary supply and buy a gallon of mineral oil U. S. P. I think it's safer that way. We hams are in interestingly cheap lot. We'll spend thousands on a new rig that could break down tomorrow and then pour a gallon of "whatever" into the dummy load instead of spending twenty bucks for mineral oil or fifty bucks for MFJs transformer oil. This in a unit that with ordinary care will last a lifetime. Sheesh! Russ "Keyboard In The Wilderness" wrote in message news:4q8Za.31351$ff.14186@fed1read01... From the Google Group Search Engine: For what it is worth The Handbook (at least my 1990 edition) has some information on this subject. In the Station Accessories chapter there are plans to build a couple of Cantenna type dummy loads. They mention an oil sold by Texaco (if I remember correctly) for turbine lubrication that is, according to the author, the same oil as is used in transformers. They quote the exact product designation. Apparently, it's sold in minimum 5 gallon quantities and I think it's about $5 per gallon. If anyone's interested, let me know and I'll look up the information and pass it along. It's supposed to be PCB-free, also. The article also cautions against using motor oil for various reasons, among which is that it attacks the resistor (actually, I think it's the additives that cause the problem). "Art Unwin KB9MZ" wrote in message m... "Keyboard In The Wilderness" wrote in message news:fjUYa.31252$ff.5358@fed1read01... Jav -- asked many times before -- for the answers go to Groups Google.com http://groups.google.com/ I don,t fully understand why motor oil should not be used in a dummy load! I need to make one so I can calibrate one of my instruments. I intend to use one of the uptodate gallon paint cans that has a PTFE liner and solder the lid on. Since we now have the means to use low wattage signals for tuning up purposes there is obviously no reason to store it in the shack . So what really is the problem with using available oil instead of emulating the aproach of industrial transformers or regurgitating old thoughts ? Art Search for Oil For Cantenna or Oil For Dummy Load Mineral Oil works well for me. "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
In article ,
Roy Lewallen wrote: DX QSOs with your dummy load count as "harsh conditions", so you've got to change the oil every 2500 DX QSOs if you don't want your dummy load wearing out early. I imagine that all of the (unradiated) CQs being fed into the dummy load end up being absorbed by the oil and eventually precipitate out as a sludge on the bottom of the can? Maybe there's a way to filter them out of the oil and recycle them. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Reg Edwards wrote: Way back in the 1970's I visited the National Physical Laboratory (NPL) at Teddington, West London. I was priviledged to see, but not to touch, the National Standards of the Ohm and of the Volt. There were a number of 4-terminal resistors submerged in a temperature-controlled oil bath. There was about a dozen Western Cells Is that something like a Weston Cell? On a serious note, don't overlook refrigeration oils, they are high quality, light, dry oils for immersed motor windings, and available in smaller sealed tins (around 5 litres). Owen |
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is far motor oil (if you have to use it ) use "nd 30" (or 40 ,20,50 the
weight is not important) the "nd" is non detergent, to not dissolve carbon i tend to agree try to find an oil closer to what's "right" bob |
Actually, the viscosity (the number indicates viscosity, not weight or
density) is important. The lower the number the better. That's one of the reasons transformer oil is better for transformers and dummy loads than drug store mineral oil - it has lower viscosity. The lower the viscosity the more easily convection currents transfer heat from the dummy load into the fluid and from the fluid to the can. That means lower thermal resistance, giving a lower resistor temperature for a given power dissipation. 73, Bob AD3K BOB wrote: is far motor oil (if you have to use it ) use "nd 30" (or 40 ,20,50 the weight is not important) the "nd" is non detergent, to not dissolve carbon i tend to agree try to find an oil closer to what's "right" bob -- Robert L. Spooner Registered Professional Engineer Associate Research Engineer Intelligent Control Systems Department Applied Research Laboratory Phone: (814) 863-4120 The Pennsylvania State University FAX: (814) 863-7841 P. O. Box 30 State College, PA 16804-0030 |
(Art Unwin KB9MZ) wrote in message om...
(Brian Kelly) wrote in message . com... "Can motor oil be used " and the correct answer is a qualified YES What API spec crankcase oils do you have in mind? If you want to leave a KILOWATT active overnight then I would certainly say NO. I certaily would recommend the Teflon coated cans since can seams can sometimes 'weep'when thin oils are used. In the case of a paint can being used for the housing for a dummy load the outer surface of the can needs to be able to radiate as much power as possible. A Teflon liner between the oil and inner surface of the metal can is a thermal insulator and will degrade the ability of the can and the dummy load to transfer the BTUs in the oil to the air surrounding the can. Simply degrease the can thoroughly and resolder the seams. Still won't get rid of all the oil forever because the relief valves burp and/or leak here and there. If viscosity is your main concern then additional circulation methods will alleviate that in a way far superior to that using the best known transformer oil ( ARRL shows a method of achieving this) I once wound a double-layer full length coil of 1/4" copper tubing which was immersed in the mineral oil and soldered into the lid of a Cantenna. I ran faucet water thru the coil. The dummy load ran quite cool under all conditions when we were key-down smoke testing 2kW output HF amps for an hour at a crack. If resisters are your main worry then use a couple of wire resisters with the windings oriented in opposite fashion since absolute accuracy is intended for real dummies. ( Note resistors change value over time even when not in hostile environments.) Check the values on an old tube/valve reciever for yourself) Dummy loads are simply places where one can dump RF power without cluttering up the bands. And I certainly wouldn't get involved with winding any inductors when non-inductive 50 Ohm deposited-film resistors are freely available. As a point of interest, have you considered what creates the first point of failure, No, I've never had a dummy load fail. and why transformers housings are built so mechanically strong ? Because they're the stuctural supports and housings for particulaly heavy AC power machinery often located outdoors and subject to all sorts of physical abuse. Plus the shells need to be of heavy enough plate to reliably facilitate leakproof welds. I fail to understand what this topic has to do with ham radio dummy load mechanicals. Can you tell me at what time the 'flash point ' comes into play when considering it.s use for a dummy load ? No, but if the flash point ever becomes a concern I'll look up the temp and take it from there. These questions go to the very point that I discussed i.e using industry methods as pointers BUT with due reference to the different environnments and duty cycles required with respect to cost and availability. .. . OK. Regards Art w3rv |
Roy Lewallen wrote in message ...
Brian Kelly wrote: In the case of a paint can being used for the housing for a dummy load the outer surface of the can needs to be able to radiate as much power as possible. A Teflon liner between the oil and inner surface of the metal can is a thermal insulator and will degrade the ability of the can and the dummy load to transfer the BTUs in the oil to the air surrounding the can. . . . Don't tell my wife that. She's been thinking all along that the food she's been putting in the Teflon lined frying pan has actually been cooking! Hee! Couple weeks ago I got stupid and tried to fry a couple eggs in a bare aluminum pan. I wound up with one edible egg and one which alloyed itself with the pan. Seriously, what you've got is a series of "thermal resistances" in series. This is a legitimate if simplified way of evaluating temperature drop, and is widely used in determining chip temperature of transistors and ICs. From the resistor, you've got the thermal resistance of the oil, in series with the thermal resistance of the Teflon, then the metal can, then finally the resistance of the can-to-air transfer, or "connection". The temperature difference between the resistor and the air is calculated like the voltage in a circuit, where the circuit's "current" is the amount of power being transferred. That is, DT = THETA * P, where DT is the temperature differential, P the power, and THETA all the thermal resistances in series. In electronics, DT is usually in degrees C, P in watts, and THETA in degrees C per watt. Yup. There isn't a steady-state thermal circuit out there which can't be modeled on the bench with a pile of resistors. Gets hairy when fluid dyanmics gets into the mix, laminar vs. turbulent flow, etc. Ditto the electrical network simulation of mechanical vibrations. A lot of grad school theses were written in the general topic area back in analog computer days. Mother Nature could care less about the lines between engineering disciplines. While the thermal resistance of the Teflon layer is undoubtedly several orders of magnitude greater than the thermal resistance of the can, I'd be willing to bet that it's much less than the can-to-air thermal resistance, Blow air on the can with a fan. In the limit dunk the can in a bucket with water running in/out. and probably (because of its very small thickness) even much less than the resistor-to-Teflon thermal resistance through the oil (unless, perhaps, the oil is very rapidly stirred). So, in the big picture, the Teflon layer doesn't make any difference. Agreed. Nobody ever died from an engineering troll. Roy Lewallen, W7EL w3rv |
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Perhaps that are types and grades of motor oil out there that will work with
certain types of resistors I dont think it very practical to research to find which are compatible. Perhaps the oil companies already know. You could make it a project to enquire with them and post the information on this news group. "Art Unwin KB9MZ" wrote in message m... Russ, The point I am making is that some comments are repeated so many times they take a life of their own Think about it, the resistors of old are a far cry from the carbon resistors of today which are not as porous, if it is a worry then coat it with epoxy ! Then there is the "rust" question, the paint cans of today have a teflon liner ! Even the latest ham data states that motor oil CAN be used ( no, it will not explode !) but raise a question of "life", possibly a suggestive comment that you change the oil every 5000 qso's. Certainly industry gives a good guide as to what is the best to use for their circumstances but it doesn't rule out every thing else for all time, and this includes motor oil of which there are many types. Regards Art Russ wrote in message . .. On 10 Aug 2003 08:19:18 -0700, (Art Unwin KB9MZ) wrote: Well it would seem that the 'don't use motor oil' comment which has been passed on by mouth to mouth over the decades doesn't seem to stand up to scruteny. Yes, the question is raised so many times over the years and the same old stories pop up, but without any substantiation such that it just appears to be gossip. One statement mentions attack on resisters, where's the proof, If it is true then it surely can be easily overcome. Hopefully this time, one of the many posters over the years on this subject will make observations that are relevant to the present day instead of waiting for a book. Art Well Art, the detergents in modern motor oils are specifically formulated to dissolve carbon deposits and sludge (largely made up of carbon) and keep in in suspension. I'm pretty sure that the resistor in my Cantenna is carbon. Transformer oil is formulated to have a high dieletric strength. Mineral oil is relatively pure, lightweight petrolatum (like liquid Vaseline(r)) and has a pretty high dieletric strength just because of low impurities. Motor oil? I don't know. ATF? I don't know about that either. What I do know is that the designers of my dummy load specify either transformer oil or mineral oil. That's good enough for me. I'll mosey on down to the transformer shop of the local electric utility and buy the folks there a round of coffee in the morning or over to the veterinary supply and buy a gallon of mineral oil U. S. P. I think it's safer that way. We hams are in interestingly cheap lot. We'll spend thousands on a new rig that could break down tomorrow and then pour a gallon of "whatever" into the dummy load instead of spending twenty bucks for mineral oil or fifty bucks for MFJs transformer oil. This in a unit that with ordinary care will last a lifetime. Sheesh! Russ "Keyboard In The Wilderness" wrote in message news:4q8Za.31351$ff.14186@fed1read01... From the Google Group Search Engine: For what it is worth The Handbook (at least my 1990 edition) has some information on this subject. In the Station Accessories chapter there are plans to build a couple of Cantenna type dummy loads. They mention an oil sold by Texaco (if I remember correctly) for turbine lubrication that is, according to the author, the same oil as is used in transformers. They quote the exact product designation. Apparently, it's sold in minimum 5 gallon quantities and I think it's about $5 per gallon. If anyone's interested, let me know and I'll look up the information and pass it along. It's supposed to be PCB-free, also. The article also cautions against using motor oil for various reasons, among which is that it attacks the resistor (actually, I think it's the additives that cause the problem). "Art Unwin KB9MZ" wrote in message m... "Keyboard In The Wilderness" wrote in message news:fjUYa.31252$ff.5358@fed1read01... Jav -- asked many times before -- for the answers go to Groups Google.com http://groups.google.com/ I don,t fully understand why motor oil should not be used in a dummy load! I need to make one so I can calibrate one of my instruments. I intend to use one of the uptodate gallon paint cans that has a PTFE liner and solder the lid on. Since we now have the means to use low wattage signals for tuning up purposes there is obviously no reason to store it in the shack . So what really is the problem with using available oil instead of emulating the aproach of industrial transformers or regurgitating old thoughts ? Art Search for Oil For Cantenna or Oil For Dummy Load Mineral Oil works well for me. "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
On Fri, 15 Aug 2003 06:31:04 GMT, "Jimmy"
wrote: Perhaps that are types and grades of motor oil out there that will work with certain types of resistors I dont think it very practical to research to find which are compatible. Perhaps the oil companies already know. You could make it a project to enquire with them and post the information on this news group. :-) It would make as much sense to fill the can with mud, add one electrode, and feed it against the shell. Some may no doubt find their life's mission in then determining what grade of oil (to replace the water) would improve this option. It would certainly offer more caloric mass than a resistor, is freely available, and all would quite agree - conductive and lossy. [How many errors can you find in this proposal? Submit answers on the back of a $20 bill and post to:] 73's Richard Clark, KB7QHC |
Man, a simple question I asked, and it's still being debated!
I'll reserve my next question, "Can I store a battery on a bare concrete floor", for another slow day. 73, -jav w6vms |
Richard Clark wrote in message . ..
On 14 Aug 2003 07:29:40 -0700, (Brian Kelly) wrote: I spent a day and a half on the phone calling around trying to buy a lousy two pounds of a specific DuPont Teflon-bearing grease. The worn-out DuPont tech rep finally wrote an order for a two pound sample but I had to drive 50 miles to the Dupey warehouse to pick it up. I imagine it's much easier to simply run a web search today. 73's Richard Clark, KB7QHC w3rv Hi Brian, That is exactly how I get all my exotic electronics parts, engineering samples. FREE. Need a 24 bit ADC? How about GHZ GBWP amps? Precision V-F-V converters? FREE. There are people who have that skill down to an art form. Unfortunately I've never been able to well in that field. Now, if I wanted to buy one they would tell me to take a hike. Right. Getting you off their phones is worth much more to them than the widget and/or the paperwork are worth . . As for your last comment about web searching. That is my current business. I build web robots and if anyone is interested, my current model that I call GrantBot will search through nearly 2000 pages of legislation funding of Grants offered and awarded by every department, agency, institute, consortium, office, bureau, center, program, group, division, administration, service, ... in the government. This offer is free to individuals. I have a generic robot that is workable, but which remains to gain recent work's improvements. However, it requires that you have some foreknowledge of potential links (it is a targeted web robot, not a free roaming one). That too is free to individuals. When I say individuals, that means those not using it as a tool of their paid work. If you are a sole proprietor, I still consider you an individual. I'm just a sole these days, not a sole proprietor. For now anyway. I freelance in the industrial machine design biz but ran out of work in March and decided to coast with my feet up on the handlebars for a few months and do some radio, etc. Which is much easier when yer finally positioned to plunder the Social Security fund like I am now. Thanks for the offer Richard but I'm unloading tools rather than acquiring new ones. 73's Richard Clark, KB7QHC w3rv |
On Fri, 15 Aug 2003 06:31:04 GMT, "Jimmy"
wrote: Perhaps that are types and grades of motor oil out there that will work with certain types of resistors I dont think it very practical to research to find which are compatible. Perhaps the oil companies already know. You could make it a project to enquire with them and post the information on this news group. Yeah, or hey! You could just use transformer oil. Art is being pedantic and difficult. Russ "Art Unwin KB9MZ" wrote in message om... Russ, The point I am making is that some comments are repeated so many times they take a life of their own Think about it, the resistors of old are a far cry from the carbon resistors of today which are not as porous, if it is a worry then coat it with epoxy ! Then there is the "rust" question, the paint cans of today have a teflon liner ! Even the latest ham data states that motor oil CAN be used ( no, it will not explode !) but raise a question of "life", possibly a suggestive comment that you change the oil every 5000 qso's. Certainly industry gives a good guide as to what is the best to use for their circumstances but it doesn't rule out every thing else for all time, and this includes motor oil of which there are many types. Regards Art Russ wrote in message ... On 10 Aug 2003 08:19:18 -0700, (Art Unwin KB9MZ) wrote: Well it would seem that the 'don't use motor oil' comment which has been passed on by mouth to mouth over the decades doesn't seem to stand up to scruteny. Yes, the question is raised so many times over the years and the same old stories pop up, but without any substantiation such that it just appears to be gossip. One statement mentions attack on resisters, where's the proof, If it is true then it surely can be easily overcome. Hopefully this time, one of the many posters over the years on this subject will make observations that are relevant to the present day instead of waiting for a book. Art Well Art, the detergents in modern motor oils are specifically formulated to dissolve carbon deposits and sludge (largely made up of carbon) and keep in in suspension. I'm pretty sure that the resistor in my Cantenna is carbon. Transformer oil is formulated to have a high dieletric strength. Mineral oil is relatively pure, lightweight petrolatum (like liquid Vaseline(r)) and has a pretty high dieletric strength just because of low impurities. Motor oil? I don't know. ATF? I don't know about that either. What I do know is that the designers of my dummy load specify either transformer oil or mineral oil. That's good enough for me. I'll mosey on down to the transformer shop of the local electric utility and buy the folks there a round of coffee in the morning or over to the veterinary supply and buy a gallon of mineral oil U. S. P. I think it's safer that way. We hams are in interestingly cheap lot. We'll spend thousands on a new rig that could break down tomorrow and then pour a gallon of "whatever" into the dummy load instead of spending twenty bucks for mineral oil or fifty bucks for MFJs transformer oil. This in a unit that with ordinary care will last a lifetime. Sheesh! Russ "Keyboard In The Wilderness" wrote in message news:4q8Za.31351$ff.14186@fed1read01... From the Google Group Search Engine: For what it is worth The Handbook (at least my 1990 edition) has some information on this subject. In the Station Accessories chapter there are plans to build a couple of Cantenna type dummy loads. They mention an oil sold by Texaco (if I remember correctly) for turbine lubrication that is, according to the author, the same oil as is used in transformers. They quote the exact product designation. Apparently, it's sold in minimum 5 gallon quantities and I think it's about $5 per gallon. If anyone's interested, let me know and I'll look up the information and pass it along. It's supposed to be PCB-free, also. The article also cautions against using motor oil for various reasons, among which is that it attacks the resistor (actually, I think it's the additives that cause the problem). "Art Unwin KB9MZ" wrote in message m... "Keyboard In The Wilderness" wrote in message news:fjUYa.31252$ff.5358@fed1read01... Jav -- asked many times before -- for the answers go to Groups Google.com http://groups.google.com/ I don,t fully understand why motor oil should not be used in a dummy load! I need to make one so I can calibrate one of my instruments. I intend to use one of the uptodate gallon paint cans that has a PTFE liner and solder the lid on. Since we now have the means to use low wattage signals for tuning up purposes there is obviously no reason to store it in the shack . So what really is the problem with using available oil instead of emulating the aproach of industrial transformers or regurgitating old thoughts ? Art Search for Oil For Cantenna or Oil For Dummy Load Mineral Oil works well for me. "Javier Henderson" wrote in message ... I got a Heathkit Cantenna recently, sans oil. Where do I find transformer oil? The few industrial suppliers in my area (Monterey, CA) want to sell me drums of the stuff. I only need a gallon... Is motor oil OK to use? 73, -jav w6vms |
On 15 Aug 2003 10:08:30 -0700, Javier Henderson wrote:
Man, a simple question I asked, and it's still being debated! Yup, every time. I'll reserve my next question, "Can I store a battery on a bare concrete floor", for another slow day. Will that be before or after asking about which editor to write web/text/??? documents? sdb -- | Sylvan Butler | Not speaking for Hewlett-Packard | sbutler-boi.hp.com | | Watch out for my e-mail address. Thank UCE. change ^ to @ | It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end, for they do so with the approval of their consciences. -- C. S. Lewis |
On Mon, 18 Aug 2003 15:44:54 -0600, Sylvan Butler
d wrote: On 15 Aug 2003 10:08:30 -0700, Javier Henderson wrote: Man, a simple question I asked, and it's still being debated! Yup, every time. I'll reserve my next question, "Can I store a battery on a bare concrete floor", for another slow day. Will that be before or after asking about which editor to write web/text/??? documents? sdb ed or ex. B^) Russ |
Sylvan Butler d writes:
On 15 Aug 2003 10:08:30 -0700, Javier Henderson wrote: I'll reserve my next question, "Can I store a battery on a bare concrete floor", for another slow day. Will that be before or after asking about which editor to write web/text/??? documents? Emacs, of course. Is there anything else? -jav |
Try the local veterinary supply you can get gallon bottles of mineral oil at a fair price,
no strange looks at the pharmacy and the cows/horses don't like small bottles. |
On 19 Aug 2003 13:44:46 -0700, Javier Henderson wrote:
Sylvan Butler d writes: On 15 Aug 2003 10:08:30 -0700, Javier Henderson wrote: I'll reserve my next question, "Can I store a battery on a bare concrete floor", for another slow day. Will that be before or after asking about which editor to write web/text/??? documents? Emacs, of course. Is there anything else? I thought the topic was editors, not shell replacements! (vi in the form of gvim for me, thanks) sdb -- | Sylvan Butler | Not speaking for Hewlett-Packard | sbutler-boi.hp.com | | Watch out for my e-mail address. Thank UCE. change ^ to @ | It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end, for they do so with the approval of their consciences. -- C. S. Lewis |
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