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Don't have a 50W dummy load

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Jim Brown-10

Re: Fw: Don't have a 50W dummy load

These are the sort of things i look for at hamfests and other electronic
flea markets (what the locals call "swap meets"). I have several 10W 50
ohm loads, 100W loads, and even one 500W load. All are commercial
quality, removed from 2-way or cell sites. And, of course, as others
have noted, always bring along a little VOM and look at the DC
resistance before buying. :)

73, Jim K9YC

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Brian Murrey

Re: Fw: Don't have a 50W dummy load

In reply to this post by W1KSZ

I think I have a roll of 12 Ohm 2w resistors at home. If you use 9 in
series and 8 in series, then connect those two stacks in parallel, you will
get 50.8 ohms, and I think about 20w of power handling...not sure on the
power...if someone wants to run that through the Cray and get the exact
number, I'd be thrilled to know it.

I will give away a set of 17 resistors to anyone that mails me a postage
paid, 4 by 6 inch, padded envelope. I think two stamps will do it...maybe
three if you are having doubts. I have used these in homebrew dummy loads
and crammed it in a Altoids tin....you need to supply a connector and the
Altoids tin.

My address is good on QRZ...

BUT WAIT UNTIL I GET HOME TONIGHT TO MAKE SURE I STILL HAVE THEM. The
spool had about 400 on it...so I hope I have it. I'll post again tonight.

73 de KB9BVN
Brian Murrey

On Thu, Mar 26, 2015 at 2:26 PM, Richard Solomon <[hidden email]>
wrote:

> You can often find Dummy loads at your local Ham Flea. I found two 50 Watt
> Birds
> for $10 each at the last one.
>
> 73, Dick, W1KSZ
>
>
> On 3/26/2015 11:15 AM, Fred Jensen wrote:
>
>> Mine works fine at 220, VSWR on 440 is about 1.3:1 and rising fast. On
>> the QRP one I made, I left about 1" leads on the resistors, I had a small
>> brass tube to connect the center conductor down to the bottom plate and I
>> didn't want to cut it. VSWR on 6 meters is 1.6:1.
>>
>> 73,
>>
>> Fred K6DGW
>> - Northern California Contest Club
>> - CU in the 50th Running of the Cal QSO Party 3-4 Oct 2015
>> - www.cqp.org
>>
>> On 3/25/2015 8:13 PM, Charlie T, K3ICH wrote:
>>
>>> Yes, but the inductances are all in parallel. I built a decent dummy
>>> load out of 24, 1200 Ohm, 10 watt wire wound resistors all in parallel
>>> between two squares of fiberglass PC board. The SWR was only about
>>> 1.2:1 on 15 Meters and about 1.5:1 on 10 meters. Admittedly, not a
>>> perfect load, but certainly adequate for the low bands just to soak up
>>> some RF.
>>>
>>> 73, Charlie k3ICH
>>>
>>>>
>>>> If you're going to use the paralleled metal film resistor construction
>>>> method, be sure to keep the resistor leads short and spaced them from
>>>> each other. Lead inductance will start to become a factor on 6 m and
>>>> up. I built mine with 40 2K 2W resistors and it works find at 100W if
>>>> used intermittently. It's air cooled. Don't know how much putting it
>>>> in oil would improve the dissipation.
>>>>
>>>
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>>
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--
73 de KB9BVN
Brian Murrey
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Russ-2

Re: Fw: Don't have a 50W dummy load

In reply to this post by Mike Reublin NF4L

Brings back memories
My cantenna as a kid needed "transformer oil". My Dad used to work at the local hydro plant. Got a whole gallon of the best PCB oil no money can buy.
73 Russ KD4JO

Sent from my T-Mobile 4G LTE Device
-------- Original message --------
From: DGB <[hidden email]>
Date:03/26/2015 1:28 PM (GMT-05:00)
To: [hidden email]
Cc:
Subject: Re: [Elecraft] Fw: Don't have a 50W dummy load

Checked my Cantenna today, 78 ohms.

Took it apart, even measured the raw resistor.

Ordered a replacement from Alan W1GA as someone else mentioned.

eBay # 221724743523 for description and options

Easy disassembly and price war right ... $24.50 shipped.

Thanks for all the info on DL's.

73 Dwight NS9I

On 3/26/2015 12:17 PM, Edward R Cole wrote:

> Just stop all this and go buy one
> Lots of them listed under "Ham Radio Dummy Load" on e-bay at about a
> buck a watt.
>
> I bought a NARDA 40w load with N-connector good to 12.6 GHz for $40
> (from a friend on-line).
> Yeah I had a 100w light bulb and a Heath Cantenna way back
>
> Now mine mostly made by Bird, NARDA, M/A, Midwest MW, etc. My 500w is
> made by Sierra and I paid maybe $50 at a flea market (it has built-in
> power meter). SWR is not quite 1:1.00 (1.4 as I recall) - so what.
>
> 73, Ed - KL7UW
> http://www.kl7uw.com
> "Kits made by KL7UW"
> Dubus Mag business:
> [hidden email]
>
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>

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k6dgw

Re: Fw: Don't have a 50W dummy load

When I came home from Vietnam in 1967, my new wife bought me a Swan 500.
Our next station was to NASA in Houston. We got settled into an
apartment, and I needed to fill my Cantenna so on Sunday [first clue],
we went to the local grocery store to get a gallon of Squibb mineral
oil. It only came in quarts so I put 4 in the basket. Checking out,
the clerk, with a big grin, [second clue] said, "You're going to drink
all of that, right?" Before I could say, "Give me a break!", she
continued, "Because if you're not, I can't sell it to you on Sunday." I
answered, "Yes," she rang it up, and with the same big grin, said as we
left, "Hope it works for ya'll."

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 50th Running of the Cal QSO Party 3-4 Oct 2015
- www.cqp.org

On 3/26/2015 12:53 PM, mundschenk55 wrote:
> Brings back memories My cantenna as a kid needed "transformer oil".
> My Dad used to work at the local hydro plant. Got a whole gallon of
> the best PCB oil no money can buy. 73 Russ KD4JO
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Eric Swartz - WA6HHQ

Re: Fw: Fw: Don't have a 50W dummy load

Administrator

In reply to this post by Elecraft mailing list

Hi bob - Your post was far from stupid. On this reflector we welcome all
questions of this type. Please feel free to post as ask as needed. You will
certainly get a lot of responses, some closer to the mark than others. At least
one will be exactly what you are looking for.

We certainly have an verbose group though! I never expected to see so many dummy
load emails in my inbox..

So let's close this thread at this time inthe interest of keeping list volume
under control.

73,
Eric
List Moderator
elecraft.com

On 3/25/2015 5:51 PM, Bob Gibson via Elecraft wrote:

> You guys are right!! SORRY FOR MY STUPID POST!! Sixty years ago I did not have money for a dummy load..ENJOY 73s Bob W5RG
>
> ----- Forwarded Message -----
> From: Fred Jensen <[hidden email]>
> To: [hidden email]
> Sent: Wednesday, March 25, 2015 6:41 PM
> Subject: Re: [Elecraft] Fw: Don't have a 50W dummy load
>
> Ummm ... several reasons. Resistance component of an incandescent bulb
> impedance varies with the temperature [brightness] of the filament.
> They are also somewhat reactive. Push-pull vacuum tubes and link
> coupling didn't care about SWR, I don't even remember the term in the
> ham lexicon until the Pi-network and 50 ohm output was invented.
>
> They're also not very good at the "dummy" part. N6BT, of Force 12 fame,
> is fairly famous for his "phased illuminator," 3 300 watt bulbs mounted
> on his deck railing in a V arrangement on which he worked all
> continents. More than once I made contacts while using a 100 watt bulb
> as my dummy load.
>
> If you're going to use the paralleled metal film resistor construction
> method, be sure to keep the resistor leads short and spaced them from
> each other. Lead inductance will start to become a factor on 6 m and
> up. I built mine with 40 2K 2W resistors and it works find at 100W if
> used intermittently. It's air cooled. Don't know how much putting it
> in oil would improve the dissipation.
>
> 73,
>
> Fred K6DGW
> - Northern California Contest Club
> - CU in the 50th Running of the Cal QSO Party 3-4 Oct 2015
> - www.cqp.org
>
>
>
>>> On Mar 25, 2015, at 14:25, Bob Gibson via Elecraft <[hidden email]> wrote:
>>>
>>> HOW ABOUT A LAMP WITH 100 WATT BLUB, THATS ALL US OLD GUYS HAD! 73s Bob W5RG
> ______________________________________________________________
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>
>
>
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Rick Stanback

Re: KPA500

In reply to this post by 'DGB'

My new KPA500 has started acting up again. It was coming up with
Invalid in the display and no high voltage. I checked the aux cables
and re-seated them and that seems to have cured the invalid error but I
still get no high voltage. It was doing this after I first built the
kit and then it just seemed to get over it and was working fine for
about a week. Any ideas on what to check the manual does not really
give you much to go on.

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wayne burdick

Re: KPA500

Administrator

Rick,

Sorry to hear about this. I've emailed everyone involved in the KPA500 product design, asking them to contact you ASAP with information about this.

73,
Wayne
N6KR

On Mar 26, 2015, at 6:35 PM, Rick Stanback <[hidden email]> wrote:

>
> My new KPA500 has started acting up again. It was coming up with Invalid in the display and no high voltage. I checked the aux cables and re-seated them and that seems to have cured the invalid error but I still get no high voltage. It was doing this after I first built the kit and then it just seemed to get over it and was working fine for about a week. Any ideas on what to check the manual does not really give you much to go on.
>
>
>
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123