Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Disposing of the entire Cantenna would be an over-reaction. The Cantenna can be opened safely, any oil within disposed of, the component parts rinsed in an approved solvent, and reassembled using mineral oil, or NON-PCB transformer oil as the coolant. Use rubber gloves, dispose of the existing coolant in an approved manner. Bottle the waste oil and used solvent it,and take it to a hazardous waste disposal site. Most city dumps will have such a facility.Non-PCB based transformer oils are often available at electrical supply houses or perhaps you can find a friend at the local power company that will give you a fill-up for the asking. The hazard to you and the environment is minimal with such a procedure. PCB based transformer oils, Askarel is the trade name for one such oil, are mildly toxic and must be handled properly, but you won't die or even get sick from a brief exposure. If you get any on your skin, which is unlikely if you use rubber or latex gloves, simply wash with solvent first then copious quantities of soap and water. An approved solvent would be Chevron 325 Thinner, also sometimes known as Stoddart solvent, or equivalent. If transformer oils were all that toxic, hundreds or even thousands of power company employees and communications techs would have tipped over by now- and that hasn't happened. PCBs were once commonly used in high voltage transformers, high voltage caps, and similar items. I am not attempting to say such materials have no hazards, it's just that such hazards are often hyped to levels that are not commensurate with the real risk. Back to your regularly scheduled reflector now. - Jim, KL7CC Dave New, N8SBE wrote: I don't like the idea of a can of oil sitting in the house, -- in particular, if you don't know what kind of oil might be lurking in that old Cantenna. Note that prior to the A suffix models, Heath recommended transformer oil, and had no warnings against using oils that contained PCBs. After PCBs were outlawed in the US, Heath changed their recommendation to mineral oil, and included a warning against the use of transformer oil of unknown composition. So, if you come across a vintage Cantenna at a ham fest, what do you think might be in it? If it's the old style with the little 'house' on top, I'd steer clear of it. The Cantenna should be disposed of, in accordance with federal law, and under no circumstances should be opened by untrained and unprotected personnel. Considering that most of these Cantennas leak around the screws on the lid, I'd be very leery of any of the 'first edition' Cantennas. The new ones, with the spiffy Red/Black logos, should be OK, but if you have any doubt, pass it by. 73, -- Dave, N8SBE Original Message Subject: Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) From: Ken Nicely k...@nicelyweb.com Date: Tue, February 23, 2010 11:11 pm To: elecraft@mailman.qth.net I have the MFJ 264 http://www.mfjenterprises.com/Product.php?productid=MFJ-264 I have been using this for about 9 months now without a problem. I use it to tune the amp putting about 500 or 600 watts into it for short periods of time with no problems. If you want a nice one that you wont outgrow for a while I would recommend it. I don't like the idea of a can of oil sitting in the house, and why have that heavy paint can full of oil sitting around when you can put this little air cooled unit on the shelf. All for about $75.00. Of course this is overkill for what you need now, but you might consider it if you ever plan on an amp in the future. Ken KE3C __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Is that Cantennas made by Elecraft?
Do I have to read all this... to get news about K3?
73 de Claude VE2FK
- Original Message -
From: Dave New, N8SBE
To: Jim Wiley
Cc: elecraft@mailman.qth.net
Sent: Tuesday, March 02, 2010 6:15 PM
Subject: Re: [Elecraft] Need to select a dummy load for K3 TX
calibration...(advice?)
Jim,
Don't know what the disposal situation is in your neck of the woods, but
where I live in SE Mich, no local hazardous disposal site will handle
the material. I asked.
I'd have to hire an 'environmental' company to come in and remove the
stuff, and then they have certain approved means of breaking down the
chemical composition to dispose of it. If you go to the EPA site on
PCBs, they have links to the companies that are approved to handle PCB
disposal.
That's why I'd steer clear of older Cantennas. It's not worth the
hassle to get one tested and then to dispose of it, if need be. It
would clearly end up costing far more than the bargain price you paid
for it in the flea market.
Note that this has nothing to do with whether you think the stuff is
dangerous or not. Our government has stepped in and decided how PCBs
are to be handled.
73,
-- Dave, N8SBE
Original Message
Subject: Re: [Elecraft] Need to select a dummy load for K3 TX
calibration...(advice?)
From: Jim Wiley jwi...@alaska.net
Date: Tue, March 02, 2010 2:48 pm
To:
Cc: elecraft@mailman.qth.net
Disposing of the entire Cantenna would be an over-reaction. The
Cantenna can be opened safely, any oil within disposed of, the component
parts rinsed in an approved solvent, and reassembled using mineral oil,
or NON-PCB transformer oil as the coolant. Use rubber gloves, dispose
of the existing coolant in an approved manner. Bottle the waste oil and
used solvent it,and take it to a hazardous waste disposal site. Most
city dumps will have such a facility.Non-PCB based transformer oils
are often available at electrical supply houses or perhaps you can find
a friend at the local power company that will give you a fill-up for
the asking.
The hazard to you and the environment is minimal with such a
procedure. PCB based transformer oils, Askarel is the trade name for
one such oil, are mildly toxic and must be handled properly, but you
won't die or even get sick from a brief exposure. If you get any on
your skin, which is unlikely if you use rubber or latex gloves, simply
wash with solvent first then copious quantities of soap and water. An
approved solvent would be Chevron 325 Thinner, also sometimes known as
Stoddart solvent, or equivalent.
If transformer oils were all that toxic, hundreds or even thousands of
power company employees and communications techs would have tipped over
by now- and that hasn't happened. PCBs were once commonly used in high
voltage transformers, high voltage caps, and similar items. I am not
attempting to say such materials have no hazards, it's just that such
hazards are often hyped to levels that are not commensurate with
the real risk.
Back to your regularly scheduled reflector now.
- Jim, KL7CC
Dave New, N8SBE wrote:
I don't like the idea of a can of oil sitting in the house, -- in
particular, if you don't know what kind of oil might be lurking in that
old Cantenna. Note that prior to the A suffix models, Heath
recommended transformer oil, and had no warnings against using oils that
contained PCBs. After PCBs were outlawed in the US, Heath changed their
recommendation to mineral oil, and included a warning against the use of
transformer oil of unknown composition.
So, if you come across a vintage Cantenna at a ham fest, what do you
think might be in it? If it's the old style with the little 'house' on
top, I'd steer clear of it. The Cantenna should be disposed of, in
accordance with federal law, and under no circumstances should be opened
by untrained and unprotected personnel. Considering that most of these
Cantennas leak around the screws on the lid, I'd be very leery of any of
the 'first edition' Cantennas. The new ones, with the spiffy Red/Black
logos, should be OK, but if you have any doubt, pass it by.
73,
-- Dave, N8SBE
Original Message
Subject: Re: [Elecraft] Need to select a dummy load for K3 TX
calibration...(advice?)
From: Ken Nicely k...@nicelyweb.com
Date: Tue, February 23, 2010 11:11 pm
To: elecraft@mailman.qth.net
I have the MFJ 264
http://www.mfjenterprises.com/Product.php?productid=MFJ-264
I have been using this for about 9 months now without a problem. I use
it
to tune the amp putting about 500 or 600 watts into it for short periods
of
time with no problems. If you want a nice
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
If you're in a hurry you've already bought the MFJ from HRO. If you want to be a little more frugal you can get an adequate one here for 12 bucks! I know it says its a 75watt load but it will do 100 for long enough to get the job done and the K3 only calibrates at 50 any way... https://www.ridgeequipment.com/store/dummyloads.html ~Brett On Tue, 2010-02-23 at 10:13 -0800, Jeff Hall, W6EZY wrote: Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
On 2/24/2010 9:41 AM, Brett Howard wrote: If you're in a hurry you've already bought the MFJ from HRO. If you want to be a little more frugal you can get an adequate one here for 12 bucks! I know it says its a 75watt load but it will do 100 for long enough to get the job done and the K3 only calibrates at 50 any way... https://www.ridgeequipment.com/store/dummyloads.html ~Brett On Tue, 2010-02-23 at 10:13 -0800, Jeff Hall, W6EZY wrote: Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.435 / Virus Database: 271.1.1/2707 - Release Date: 02/24/10 07:34:00 The same seller is selling this dummy load for less on ebay and the shipping is less via ebay. http://cgi.ebay.com/50-Ohm-Dummy-Load-75-Watts-VERY-NICE-1973_W0QQitemZ250584212024QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a57fba238 Don, N0YE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
. nice load but it's about $9 to ship it so total will run about $21 ... still a good deal! Thanks Brett! -Original Message- From: Brett Howard br...@livecomputers.com To: Jeff Hall, W6EZY w6...@arrl.net Cc: elecraft@mailman.qth.net Sent: Wed, Feb 24, 2010 11:41 am Subject: Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) If you're in a hurry you've already bought the MFJ from HRO. If you want to be a little more frugal you can get an adequate one here for 12 bucks! I know it says its a 75watt load but it will do 100 for long enough to get the job done and the K3 only calibrates at 50 any way... https://www.ridgeequipment.com/store/dummyloads.html ~Brett On Tue, 2010-02-23 at 10:13 -0800, Jeff Hall, W6EZY wrote: Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
FWIW - Last time I spoke with the folks at Ridge Equipt., they had 'a few' 100W-150W loads available as well as those shown on their web page... apparently not enough to make it worth reworking the web page to show them however. You might want to give them a phone call and see what they might have that's not shown on the web site 410 549-7661. Those they show on the site are GREAT and well worth the $$. Though they will 'handle' short periods of overload, I'd not do so for very long at all. They are 'rated' for 100% duty cycle at something BELOW the 'advertised' power levels... e.g. the 75W dummy load is more conservatively rated (elsewhere) at 65W, and, after having looked inside the load (I have one) I'd not want to push my luck too far by exceeding 65W for too long a time. They're good, but they're NOT SUPERMAN! 73, Tom N0SS At 11:22 02/24/2010, Don Nelson wrote: On 2/24/2010 9:41 AM, Brett Howard wrote: If you're in a hurry you've already bought the MFJ from HRO. If you want to be a little more frugal you can get an adequate one here for 12 bucks! I know it says its a 75watt load but it will do 100 for long enough to get the job done and the K3 only calibrates at 50 any way... https://www.ridgeequipment.com/store/dummyloads.html ~Brett On Tue, 2010-02-23 at 10:13 -0800, Jeff Hall, W6EZY wrote: Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.435 / Virus Database: 271.1.1/2707 - Release Date: 02/24/10 07:34:00 The same seller is selling this dummy load for less on ebay and the shipping is less via ebay. http://cgi.ebay.com/50-Ohm-Dummy-Load-75-Watts-VERY-NICE-1973_W0QQitemZ250584212024QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a57fba238 Don, N0YE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Don, He is *offering* it up for bid at a starting price of $9.99 - that is not the same as selling it. Who knows the bidding may go up to $50 before the 3 days have ended. So many people tell me about things like that quoting the bid price, but when I look, the price is always higher. Please clarify if it is a bidding price or a selling price (as in BUY NOW) BTW, the Ridge Equipment dummy loads are very good. Too bad they no longer have the 200 watt load nearly flat up to 1 GHz. I should have gotten 2 or 3 instead of only one. 73, Don W3FPR Don Nelson wrote: The same seller is selling this dummy load for less on ebay and the shipping is less via ebay. http://cgi.ebay.com/50-Ohm-Dummy-Load-75-Watts-VERY-NICE-1973_W0QQitemZ250584212024QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a57fba238 Don, N0YE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Ridge has been a good source of O'Scope's and repair items also ... they had the original manuals and a couple of parts I needed for my Tek 2445A scope at very fair prices. They also have excellent customer service! I didn't buy the 200 Watt load ... thought I'd wait ... really a Senior Moment as it turns out. 73, Mike N9QR In a message dated 2/24/2010 1:06:46 P.M. Eastern Standard Time, w3...@embarqmail.com writes: Don, He is *offering* it up for bid at a starting price of $9.99 - that is not the same as selling it. Who knows the bidding may go up to $50 before the 3 days have ended. So many people tell me about things like that quoting the bid price, but when I look, the price is always higher. Please clarify if it is a bidding price or a selling price (as in BUY NOW) BTW, the Ridge Equipment dummy loads are very good. Too bad they no longer have the 200 watt load nearly flat up to 1 GHz. I should have gotten 2 or 3 instead of only one. 73, Don W3FPR Don Nelson wrote: The same seller is selling this dummy load for less on ebay and the shipping is less via ebay. http://cgi.ebay.com/50-Ohm-Dummy-Load-75-Watts-VERY-NICE-1973_W0QQitemZ250584212024QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3a57fba238 Don, N0YE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX, calibration...(advice?)
I agree with everything that's been said about the Ridge loads. I have been recommending them for a couple years to customers of the LP-100A kit for use in calibration. One note: make sure you have an appropriate BNC to N adapter as their loads tend to all have N connectors (usually male). 73, Larry N8LP Date: Wed, 24 Feb 2010 13:00:02 -0500 From: Don Wilhelm w3...@embarqmail.com Subject: Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) To: Don Nelson n...@comcast.net Cc: elecraft@mailman.qth.net Message-ID: 4b856922.7030...@embarqmail.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Don, He is *offering* it up for bid at a starting price of $9.99 - that is not the same as selling it. Who knows the bidding may go up to $50 before the 3 days have ended. So many people tell me about things like that quoting the bid price, but when I look, the price is always higher. Please clarify if it is a bidding price or a selling price (as in BUY NOW) BTW, the Ridge Equipment dummy loads are very good. Too bad they no longer have the 200 watt load nearly flat up to 1 GHz. I should have gotten 2 or 3 instead of only one. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Yea its 21 bucks but I really like mine! I've got a Bird dummy that is flat to about 3Ghz and can handle 100W 100% duty cycle but I find the Ridge Equipment one to be more than enough most of the time... ~Brett (KC7OTG) On Wed, 2010-02-24 at 12:29 -0500, n...@aol.com wrote: . nice load but it's about $9 to ship it so total will run about $21 ... still a good deal! Thanks Brett! -Original Message- From: Brett Howard br...@livecomputers.com To: Jeff Hall, W6EZY w6...@arrl.net Cc: elecraft@mailman.qth.net Sent: Wed, Feb 24, 2010 11:41 am Subject: Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) If you're in a hurry you've already bought the MFJ from HRO. If you want to be a little more frugal you can get an adequate one here for 12 bucks! I know it says its a 75watt load but it will do 100 for long enough to get the job done and the K3 only calibrates at 50 any way... https://www.ridgeequipment.com/store/dummyloads.html ~Brett On Tue, 2010-02-23 at 10:13 -0800, Jeff Hall, W6EZY wrote: Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Jeff, I would consider an ohm meter reading of a non-inductive resistor to be a better indicator of low SWR than any available SWR meter including the famous Bird (available since about 1940 or before). My MFJ-989C tuner includes a dummy load rated at 300 watts. It appears identical to the 50 ohm resistor in my 35 year old Heath Cantenna but without the can of cooling oil. I also have a 15 watt dummy load that I bought from Radio Shack about 20 years ago that measures 50 or 51 ohms. I would consider any of these good enough to calibrate a watt meter or an SWR meter. Rectifying and measuring the RF voltage will probably induce more error than the resistor. Willis 'Cookie' Cooke K5EWJ From: Jeff Hall, W6EZY w6...@arrl.net To: elecraft@mailman.qth.net Sent: Tue, February 23, 2010 12:13:39 PM Subject: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
On Tue, 23 Feb 2010 10:13:39 -0800, Jeff Hall, W6EZY w6...@arrl.net wrote: I don't know about the MFJ dummy loads, but I would get low powered air cooled load for it. I use a 25 watt air cooled that I got at a ham fest for most of the testing here. Beware and take an ohm meter with you if you plan to buy one at a ham fest. Not long ago I bought what I thought was a 50 ohm 300 watt air cooled dummy load. When I got it home it measured 78 ohms. Tom, N5GE n...@n5ge.com K3 #806 with SUB RX, K3 #1055, PR6, XV144, XV432, KRC2, W1, 2 W2's and other small kits 1 K144XV on order http://www.n5ge.com http://www.swotrc.net I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Jeff, The MFJ will work just fine. I use a similar one from Drake which is air cooled for 100 watts. You should not put in a KW into the dummy load...but the MFJ would work OK. MFJ-260C. At 100 watts out...you can use it for 1.5 minutes. Or 25 watts continuous. This should work fine for what you need. Lee - K0WA Ham Radio Operators: Kansas QSO Party is August 28-29, 2010. See www.ksqsoparty.org for details In our day and age it seems that Common Sense is in short supply. If you don't have any Common Sense - get some Common Sense and use it. If you can't find any Common Sense, ask for help from somebody who has some Common Sense. Is Common Sense divine? Common Sense is the image of the Creator expressing revealed truth in my mind. - J. Wolf From: Jeff Hall, W6EZY w6...@arrl.net To: elecraft@mailman.qth.net Sent: Tue, February 23, 2010 12:13:39 PM Subject: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
At 11:13 AM 23/02/10, you wrote: Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. How about the Elecraft DL1. It's easy to build, works great! John k7up __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
Jeff: It all depends on the power level you want the load to handle. Do you want to acquire now a dummy load that will handle the output of a KW amplifier in the future, or just the output of your K3? If it's just the K3, then the MFJ-260C at $40 or so should be fine for 100W for extended periods at the calibration frequencies from 3.7 - 52 MHz. I burned up a much smaller MFJ unit that was an integrated PL-259 and a cylindrical heat sink that could handle 100 watts for very very short periods. During K3 Utility development I stopped the Tx Gain calibration code with a debugger with K3 key down for a bit too long and it Is No More. I don't find that unit in MFJ's catalog now, though. The Tx Gain calibration holds key down for a few seconds (maybe two to ten) on each HF band at 5 and 50 watts in quick succession. You might want to acquire a BNC to PL-259 adapter so that you can put your 50 ohm dummy load onto the XVTR OUT BNC connector for the milliwatt Tx Gain calibration step. That calibration really wants a 50 ohm load, although the power requirement is very small. For K3 Utility development when I run Tx Gain calibration over and over, I keep a Elecraft DL-1 on the XVTR out connector and an AEA DL-1500 (which is overkill) on the main rig ANT2 connector. 73 de Dick, K6KR -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jeff Hall, W6EZY Sent: Tuesday, February 23, 2010 10:14 AM To: elecraft@mailman.qth.net Subject: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
In the good old days you would just build one. Six 300 ohm 1W resistors in parallel between a couple of sheets of PC board, tin can lids or whatever, with a coax connector mounted on one side and the center conductor attached to the opposite sheet and you're done. Older ARRL Handbooks showed something like this---at least my 1999 does---but the new-fangled ones assume that you will buy one. Pity. I assume you're in a hurry so go to HRO and get the MFJ, it will be entirely adequate, as long as they remembered to solder the connections inside. Wes --- On Tue, 2/23/10, Jeff Hall, W6EZY w6...@arrl.net wrote: From: Jeff Hall, W6EZY w6...@arrl.net Subject: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?) To: elecraft@mailman.qth.net Date: Tuesday, February 23, 2010, 11:13 AM Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. HRO is just up the road and they carry some of the less expensive MFJ dummy loads -- would these be sufficient? Not looking to spend a lot of money, but don't want to buy junk either. What factors should I consider? I'm assuming oil-cooled dummy loads are more robust, while air-cooled loads are more compact, but you have to be more careful when operating or they can burn up more easily. The K3 manual says this is just a 5W test and I need a load with low VSWR from 160 to 6. What is considered low SWR? Anything under 1:5? If I can get by with the MFJ-260 for just $40, that sounds reasonable to me. 73 de Jeff, W6EZY __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
I used the DL1 for the 50 watt test and it worked fine. I only transmitted for a few seconds, to get a reading. It gets hot fast, at 50 watts! 73, Rick Dettinger K7MW On Feb 23, 2010, at 10:32 AM, John wrote: At 11:13 AM 23/02/10, you wrote: Hello all, I need help picking out a proper dummy load to use for calibrating my new K3. How about the Elecraft DL1. It's easy to build, works great! John k7up __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Need to select a dummy load for K3 TX calibration...(advice?)
I have the MFJ 264 http://www.mfjenterprises.com/Product.php?productid=MFJ-264 I have been using this for about 9 months now without a problem. I use it to tune the amp putting about 500 or 600 watts into it for short periods of time with no problems. If you want a nice one that you wont outgrow for a while I would recommend it. I don't like the idea of a can of oil sitting in the house, and why have that heavy paint can full of oil sitting around when you can put this little air cooled unit on the shelf. All for about $75.00. Of course this is overkill for what you need now, but you might consider it if you ever plan on an amp in the future. Ken KE3C __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
