On 12/04/2008 07:22, W8DIZ posted:
Here is the design of the SWR Bridge
http://kitsandparts.com/bridge.php
Prototype will be received on Dec 5, 2008

-Diz
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On 12/17/2008 17:53, w8iff posted:
Guess I need a Stockton Bridge for my 80M SSB transceiver.
Get me one of them in the new year.
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On 12/26/2008 03:08, KC7DXE posted:
I've been reading up on KD1JV power and SWR kit. I just found your directional coupler swr bridge. I'm looking to make a bridge for 2 m band so I can learn to make antennas more efficient.
Can you kit be modified for 2 meter or should I keep trying to get one of KD1JV's kits?
Rob
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On 12/26/2008 09:54, W8DIZ posted:
[KC7DXE wrote:] "I've been reading up on KD1JV power and SWR kit. I just found your directional coupler swr bridge. I'm looking to make a bridge for 2 m band so I can learn to make antennas more efficient.
Can you kit be modified for 2 meter or should I keep trying to get one of KD1JV's kits?
Rob
"


Hi Ron,
I will test it myself on 2 meters and check the results in a few weeks.
I would think that you can replace the FT50-43 with FT50-61 ferrites and make it work on 2 meters.
The SWR bridge will be available in about the 3rd week of January.
If you order the kit, let me know if you want me to substitute the ferrites.
73, Diz, W8DIZ
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On 04/02/2009 14:51, ki4mmm posted:
Diz,

Is the meter output of the bridge in the 50uV range, 200uV range, or some other?

Thanks,
Greg
ki4mmm
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On 04/02/2009 21:54, W8DIZ posted:
[ki4mmm wrote:] "Diz,
Is the meter output of the bridge in the 50uV range, 200uV range, or some other?
Thanks,
Greg
ki4mmm
"


Hi Greg,
The meter/output is not specified.
Based on some "playing around", you should be able to use any meter from 50uV to 1mA and maybe even higher current meter but anything less than 1 mA will work for sure.
-Diz
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On 04/03/2009 05:19, ki4mmm posted:
Thanks Diz - I have several of those little 3/4x2" rectangular 200uA meters so it sounds like I outta be able to put a couple of them to use.....

Greg
ki4mmm
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On 04/14/2009 16:22, ki4mmm posted:
I built my bridge this past weekend - it went together quickly and works great! Just to coaberate what Diz said about the flexibility with meters, there was plenty of adjustment range on the pots for my 50uV and 200uV meters, and there appeared to be plenty of range above that (i.e., approaching 1mA).

Greg
ki4mmm
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On 04/15/2009 18:22, kc0wox posted:
Hey Greg!
I talked to you yesterday and you didn't tell me you made a new Diz kit.
Bad Boy!
Leonard
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On 04/15/2009 18:23, kc0wox posted:
I may not be posting much or building any of Diz's kits lately but I read every day.
Leonard
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On 04/15/2009 21:13, ki4mmm posted:
[kc0wox wrote:] "Hey Greg!
I talked to you yesterday and you didn't tell me you made a new Diz kit.
Bad Boy!
Leonard
"


We we're so busy talking about different projects that I didn't remember this one. A week before that, I finished building all of the modules needed for a transceiver (just about every module Diz offers except the 5W CW amp) ;-).

I've got a few pairs of 200uA meters left if anyone needs some (maybe trade for a small component or two?). I'll have mine mounted in a box in a few days and will post a picture. I am going to do dangling coax w/ BNC for the input/output so I can just plug it straight into my rigs and tuners, not needing separate cables.

Greg
ki4mmm
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On 10/19/2009 22:44, k3jls posted:
Hi Diz,

I have a question about your directional coupler. I'm building an automatic tuner for a mag loop antenna driven by a stepper motor. So far, it works very, very well.

What I need, however, is a good directional coupler that I can place in an out-of-the way spot to both eliminate any possible RF contamination of the microprocessor (none detected thusfar) and to remove another pair of coax cables from the desktop.

I was wondering if your directional coupler - designed for a max power of 10 watts - would work in a 100 watt HF application if I replaced the 1/4 watt resistors with 10 watt units. Would everything else on the board hold up OK??

If so, I'll place my order tomorrow (HIHI).

Thanks, in advance, for your interest and help.

73's - Joe - K3JLS
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On 10/23/2009 15:00, W8DIZ posted:
[k3jls wrote:] "Hi Diz,

I have a question about your directional coupler. I'm building an automatic tuner for a mag loop antenna driven by a stepper motor. So far, it works very, very well.

What I need, however, is a good directional coupler that I can place in an out-of-the way spot to both eliminate any possible RF contamination of the microprocessor (none detected thusfar) and to remove another pair of coax cables from the desktop.

I was wondering if your directional coupler - designed for a max power of 10 watts - would work in a 100 watt HF application if I replaced the 1/4 watt resistors with 10 watt units. Would everything else on the board hold up OK??

If so, I'll place my order tomorrow (HIHI).

Thanks, in advance, for your interest and help.

73's - Joe - K3JLS
"


Hi Joe,
I think I answered this question via regular email...did not se the forum question...sorry.
For higher power, you would need to change the toroids to -61 or -2 material and increase the multiturn windings.
Also increase the 50 ohm resistors to 1 or 2 watts.
-Diz
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On 12/05/2009 08:53, ak2b posted:
[img]http://tomnyc.no-ip.org/images/swrbridge.jpg[/img]
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On 12/05/2009 08:54, ak2b posted:
My version of the bridge with two cheap meters from Dans Small Parts and Kits
http://www.danssmallpartsandkits.net/ (Dan's is closed until February)
Yes, I know they are 'S' meters but they tell me what I need to know at a glance -
mainly that I'm not transmitting into a high SWR. The top is forward power and the
bottom is reverse. I calibrated them as per instructions. This is a simple kit to build
and has already paid for itself in my SW20+ :)

[img]http://tomnyc.no-ip.org/images/swrbridgemeters.jpg[/img]
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On 12/05/2009 11:11, wa2mze posted:
So 'stock' this bridge is for < 10W? And it can be modified for higher power?
I have a pair of identical 50ua meters, I suspect a pot in series with the meters would be a good idea to adjust the full scale reading depending on the power level being used.
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On 12/05/2009 12:05, ak2b posted:
[wa2mze wrote:] "So 'stock' this bridge is for < 10W? And it can be modified for higher power?"


Hi Ken,

Right above my first picture, Diz has an answer to that question.

Tom, ak2b
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On 12/05/2009 12:22, wa2mze posted:
Theres quite a bit of difference between -61 and -2 material!
-2 is the RED powdered iron material with a large AL good for up to about 10 mhz.
-61 is FERRITE with lower AL than -43, but sill a lot higher than -2 and generally rated quite a bit
lower in frequency. Type 43 and 61 are used in broadband transformers and power inverters, while
2 type is used in tuned circuit transformers. I suppose type 2 could be used in broad band transformers
but it's loss would be higher and I'm not sure about the frequency range in this mode.

Maybe Diz can clear this up for me....
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On 12/05/2009 15:52, W8DIZ posted:
[wa2mze wrote:] "Theres quite a bit of difference between -61 and -2 material!
-2 is the RED powdered iron material with a large AL good for up to about 10 mhz.
-61 is FERRITE with lower AL than -43, but sill a lot higher than -2 and generally rated quite a bit
lower in frequency. Type 43 and 61 are used in broadband transformers and power inverters, while
2 type is used in tuned circuit transformers. I suppose type 2 could be used in broad band transformers
but it's loss would be higher and I'm not sure about the frequency range in this mode.
Maybe Diz can clear this up for me....
"


-43 material has the highest loss. Next is -61 and -2 has the lowest loss.
Don't be afraid to experiment :)
-Diz
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On 12/06/2009 11:00, wa2mze posted:
That seems the opposite of what we want, IE: for low power you would want the lowest loss so as to be able to drive the meters and for high power you'd want the highest loss since you don't need much left to drive the meters. Yet you've got it backwards.
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On 12/06/2009 19:06, W8DIZ posted:
[wa2mze wrote:] "That seems the opposite of what we want, IE: for low power you would want the lowest loss so as to be able to drive the meters and for high power you'd want the highest loss since you don't need much left to drive the meters. Yet you've got it backwards."


Not exactly :)

At QRP levels, I am not concerned about heating (loss) of the toroid core.
The -43 materials works BEST for broadband use; excellent for low power; low heating.
At higher power levels, the -43 material gets too hot so we use -61 or -2 material

The -43 may have more losses but I am not concerned about 10 percent loss which equates to NIL at the receiver end.

The more power, the lower the AL value (of the toroid) should be to prevent heating.
We are talking about a STOCKTON BRIDGE here.

73, Diz
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On 12/17/2009 12:58, aj4oe posted:
Any one know where I can locate 'small panel meters' for the swr bridge, small enough to fit on an Altoids tin?

Thanks for your time and help...

Rex, AJ4OE
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On 12/17/2009 14:16, W4GNS posted:
I found some with a Google search, but they cost BIG money, If you use CB meters like Tom has shown they will be cheap. They could be had used from your local CB Hack shop cheap enough I would think, and as Tom has noted Dan's Small Parts will be closed for awhile yet.

[aj4oe wrote:] "Any one know where I can locate 'small panel meters' for the swr bridge, small enough to fit on an Altoids tin?

Thanks for your time and help...

Rex, AJ4OE
"


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On 12/17/2009 15:35, ak2b posted:
Hi Rex,
I would check ebay from time to time. Finding one that will fit in an Altoids tin will be a problem. An alternative metering system, like LED's might prove to be a better solution.
Tom, ak2b
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On 12/17/2009 16:16, kc0wox posted:
Ebay is your friend for parts! I buy most of my common stuff from there.
Leonard
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On 12/19/2009 22:04, aj4oe posted:
Thanks guys... I appreciate your support and recommendations.
**** Using LEDs would suit me ****. Any recommendations about what I should get? I could get a couple like those provided in the 40 Meter Tunner-Upper.

- The CB panel meters would be my preference. I'll start calling around the CB repair shops .

Tks Again,

Rex AJ4OE
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On 12/27/2009 18:27, ak2b posted:
Hi Rex,
I thought about LED's also. M0WYM made up a device for the BitX20 that would probably work. LED Bargraph The chip doesn't seem to be readily available from standard parts suppliers, however. I went looking around for something similar and found this from Mouser, 526-NTE1561, that looks like a good candidate. It's $3.00. The drawback, in your case (assuming you wanted a stand-alone unit ) is now you would need to supply voltage. Used in a rig, this wouldn't be a problem.

Tom, ak2b
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On 02/16/2010 16:12, powerdad posted:
Hello all,
I work for an electric utility that uses radios in the 30kHz to 300kHz range to signal between substations (think FSK and on/off keying). Anyway, we currently cannot continuously monitor SWR. Can this kit be modified for this frequency range? ...different toroids?

Thanks in advance, Mike
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On 02/16/2010 16:58, W8DIZ posted:
[powerdad wrote:] "Hello all,
I work for an electric utility that uses radios in the 30kHz to 300kHz range to signal between substations (think FSK and on/off keying). Anyway, we currently cannot continuously monitor SWR. Can this kit be modified for this frequency range? ...different toroids?
Thanks in advance, Mike
"


Hi Mike,
I don't see why not. How much RF power are the radios generating?
You may want to contact me private on my email: w8diz at tampabay.rr.com
73, Diz, W8DIZ
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On 05/10/2010 17:27, SA5BKE posted:
Hi,

Im a newbie here. I just ordered a couple of items, and one of them is the SWR bridge. I just started looking for panel meters to use. Im a bit uncertain what I can get. I found these two on ebay:

http://cgi.ebay.com/Analog-AMP-Current-Panel-Meter-50-uA-Meters-85C1-/220479626086?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item33559c1b66

http://cgi.ebay.com/0-100-A-panel-meter-DC-class-2-5-NOS-Lot-1-/260558130817?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item3caa798e81

What do you think about them? I will be glad if someone could confirm that they think it will work. What caught my attention and what I wonder about is the "only DC" part on the first one.

Thanks in advance

Eric SA5BKE
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On 05/10/2010 17:55, ak2b posted:
Hi Eric,

I don't think you will have a problem with either meter. You should have enough adjustment range to handle 50 or 100 ua. The meters I used were 100ua.

Tom, ak2b
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