| Author |
Message |
    
Road_warrior
Intermediate Member
Username: Road_warrior
Post Number: 210
Registered: 7-2004
| | Posted on Tuesday, December 14, 2004 - 1:11 am: | 
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I notice Dosy makes a switchbox that allows
you to run your beam on Vert and Horz at
the same time./ How would a Maco shooting Star
react in this position???/ What the advantages
and disavantages of using this mode.???
JIM/CENTRAL PA/CEF 375 |
Geekster
Intermediate Member
Username: Geekster
Post Number: 131
Registered: 6-2004
| | Posted on Tuesday, December 14, 2004 - 9:57 am: |
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PDC made a PDC 4DX similar to this. You can use this for antenna (co)phasing. I wouldn't transmit through that position unless you have the antennas (co-phased) setup to do so.
A good thing this is for is when skip conditions occur. When the wave bounces at times it can change polarization and with the switch in that position you can get better RX results.
You can also use that position for a few other tricks too. Also if you have dual radios and want to monitor two seperate frequencies on CB for example. Just don't transmit unless you switch the coax position.
I am sure there are other uses for it too. |
477
Member
Username: 477
Post Number: 87
Registered: 6-2002
| | Posted on Wednesday, December 15, 2004 - 5:03 am: |
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Dosy makes a switch box that allows you to receive on vertical and horizontal at the same time only so you cannot transmit... is this correct? If so what is the going price of this product? |
Tech808
Moderator
Username: Tech808
Post Number: 4312
Registered: 8-2002
| | Posted on Wednesday, December 15, 2004 - 8:53 am: |
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477,
D60-07020 DOSY SW-4 4 Position Switch Box
$ 27.99
Features
4 Position Coaxial Switch Box
Low Insertion Loss
Handles up to 1000 Watts
DOSY Professional Architecture
Printed Circuit Board
Automatic SWR Compensation
Vertical/Horizontal/Auxiliary/Horizontal + Vertical Positions
****
To Order one click on the Link Below:
http://www.copperelectronics.com/cgi-bin/checkitout/checkitout.cgi?catalogSTORE:CKIE:prodD60-07020+
Hope this helps.
Lon
Tech808
CEF808
N9OSN
|
Road_warrior
Intermediate Member
Username: Road_warrior
Post Number: 214
Registered: 7-2004
| | Posted on Wednesday, December 15, 2004 - 2:08 pm: |
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So, on this Vert+Horz position, you can listen,
but, not transmit./
What needs done to the Antenna to be able to
transmit???? And will this effect still using just Vert or Horz?????
JIM/CENTRAL PA/CEF 375
|
Diggerodell
Member
Username: Diggerodell
Post Number: 74
Registered: 1-2002
| | Posted on Wednesday, December 15, 2004 - 5:49 pm: |
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i talked on mine in that position......... |
Bruce
Senior Member
Username: Bruce
Post Number: 1882
Registered: 9-2003
| | Posted on Wednesday, December 15, 2004 - 7:14 pm: |
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I have 2 boxes simular to that DOSY you CAN transmitt into both antennas at the same time however your VSWR will be high. Also remember even if you MATCH them you will have a 3 db loss in each. |
Road_warrior
Intermediate Member
Username: Road_warrior
Post Number: 215
Registered: 7-2004
| | Posted on Wednesday, December 15, 2004 - 8:01 pm: |
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Ok, thanks Bruce & everyone./ Appreciate the
info!/
JIM/CENTRAL PA/CEF 375 |
477
Member
Username: 477
Post Number: 88
Registered: 6-2002
| | Posted on Wednesday, December 15, 2004 - 8:53 pm: |
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Thanks LON for the info on the price. Now I can replace one of my old ones.
CEF:227Pa. |
Tech833
Moderator
Username: Tech833
Post Number: 909
Registered: 8-2002
| | Posted on Thursday, December 16, 2004 - 5:12 pm: |
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Bruce,
You are incorrect. A little.
If you install the Dosy switch on your dual polarity beam, switch it to dual polarity position, and your coax cables are the EXACT same length and type of cable (preferable off the same spool), then you will have a cross polarised signal. If you shorten one coax by 1/4 electrical wavelength, you will have circular polarization. If you shorten one coax by 1/2 electrical wavelength, you will have a lossy dummy load. |
Road_warrior
Intermediate Member
Username: Road_warrior
Post Number: 217
Registered: 7-2004
| | Posted on Thursday, December 16, 2004 - 10:43 pm: |
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Tech 833,
How high does the SWR jump when switched to the
dual polarity position on the dosy???
With coaxs of equal length, same type.
JIM/CENTRAL PA/CEF 375 |
Tech833
Moderator
Username: Tech833
Post Number: 914
Registered: 8-2002
| | Posted on Friday, December 17, 2004 - 1:09 pm: |
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It all depends on your loads of the two cables summed. If each is a perfect 50 ohms, then the sum will be 25 ohms. Assuming the reactances are both j0, then your SWR will only be slightly higher. However, if the loads are both reactive the same side of j, then the SWR will get pretty high. |
Tech833
Moderator
Username: Tech833
Post Number: 917
Registered: 8-2002
| | Posted on Sunday, December 19, 2004 - 11:03 pm: |
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Here is how I use my Dosy antenna switch-
The Collins R390A reeiver is connected to the VERT input. The Zenith M660 receiver is connected to the HORIZ input. The Kenwood transceiver is connected to the AUX input. I can run the two SW receivers at the same time, no problem. In this way, I cannot accidentally transmit on the Kenwood into the Collins or the Zenith. |
Road_warrior
Intermediate Member
Username: Road_warrior
Post Number: 224
Registered: 7-2004
| | Posted on Monday, December 20, 2004 - 11:16 pm: |
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Nice setup Tech 833... thanks again
JIM/CENTRAL PA/CEF 375 |
