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Norcal Doublet


johnk4qq@...
 

Thanks for the response to my post.  Have given up on Norcal Doublet and erected 33ft long  wire with counterpoise.  SWR good on 20 and 30 and flat on 40 (my favorite band). 73, John, K4QQ

 

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Ron Hayes <ka2rrz@...>
 

How long was your counterpoise ?


On Thursday, February 2, 2017 9:12 AM, "johnk4qq@... [4sqrp]" <4sqrp@...> wrote:


 
Thanks for the response to my post.  Have given up on Norcal Doublet and erected 33ft long  wire with counterpoise.  SWR good on 20 and 30 and flat on 40 (my favorite band). 73, John, K4QQ
 
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wa2cky
 

John, could you provide a few details on your antenna and feed arrangement.   Is your 33 ft all vertical orientation?   I need to have something on 40M and getting 20M would be a bonus.

73
Bob Groh, WA2CKY

On Thu, Feb 2, 2017 at 9:11 AM, johnk4qq@... [4sqrp] <4sqrp@...> wrote:
 

Thanks for the response to my post.  Have given up on Norcal Doublet and erected 33ft long  wire with counterpoise.  SWR good on 20 and 30 and flat on 40 (my favorite band). 73, John, K4QQ

 

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Curt
 

John

interesting - maybe the feedline was giving you issue perhaps, so you got rid of it? 

it is not completely insuitive - but the Norcal doublet sought to make an antenna without having twin-lead to feed it.  the feed method is similar, except for the 2 extra conductors in-between.  being in-between the feedline, those extra conductors should not radiate much - but how everything is connected inside the shack could have some impact. 

sometimes when a balanced feedline is very close to a quarterwavelength it can cause problems, so its a possibly explanation for high SWR on 40m.  do note such an antenna is expected to not have a good VSWR, as the feedline impedance may not match the antenna feed impedance.  

as for your 'counterpoise' - note that likely it is also a radiator.  if it is inside your house, how much of its radiation is useful may be low. 

keep in mind that a good VSWR is not a measure of an effective antenna -- in fact the 'best' VSWR could be from a 50 ohm resistor! 

there is both art and science to developing a useful radiator.  possibly the norcal doublet may have worked reasonably with a different feedline length, but it would be better if you found (or made) some twin lead or open wire line.  folk have use end-fed antennas for a long time - but do expect some radiation from your counterpoise.  you may with to explore the end fed half wave antenna - but please note it requires a special matching network to work effectively.  antennas need not be 'ideal' - as I use a ladder-line fed off-center feed arrangement with my 20/30/40m rig to provide all 3 bands.  okay for QRP CW, I would not want to use for high power SSB for example. 

73 Curt


Paul Smith
 

I have been reading with interest the talk of the Norcal Doublet not working well. I built 2 of them and they still live in my go kit antler box. One is built exactly like the Norcal article out of "ribbon wire" andf the other is fed with 300 ohm tv antenna wire. I tuned them both with the Norcal BLT tuner. In the spring I will see if the KX2 ATU will tune them. I have had good contacts on both using a Blackwidow crappie pole for support. YMMV de Paul N0NBD


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From: 4sqrp@... <4sqrp@...> on behalf of Bob Groh bob.groh@... [4sqrp] <4sqrp@...>
Sent: Thursday, February 2, 2017 5:21 PM
To: 4sqrp@...; johnk4qq@...
Subject: Re: [4sqrp] Norcal Doublet
 
 

John, could you provide a few details on your antenna and feed arrangement.   Is your 33 ft all vertical orientation?   I need to have something on 40M and getting 20M would be a bonus.

73
Bob Groh, WA2CKY

On Thu, Feb 2, 2017 at 9:11 AM, johnk4qq@... [4sqrp] <4sqrp@...> wrote:
 

Thanks for the response to my post.  Have given up on Norcal Doublet and erected 33ft long  wire with counterpoise.  SWR good on 20 and 30 and flat on 40 (my favorite band). 73, John, K4QQ

 

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John Adams <johnk4qq@...>
 

I live in an HOA subdivision and am severely restricted with reference to antennas. The 33ft. End fed wire is erected as a sloper running out of an upstairs bedroom to a small tree in the yard. The 33ft. counterpoise runs along the baseboard in the hall. SWR, as measured by the internal tuner in the Kx1 is as follows: 20m, 1.4; 30m, 1.0, 40 m, 1.0. This antenna is recommended by K1YPP who has done extensive portable operation, including walking the AT from Georgia to Maine, making at least one contact from each state. The speaker wire is not desirable as a permanent antenna due to exposure to the elements. I plan on replacing it later with AWG 26 stealth wire and using the speaker wire for portable operation. I have been a ham for 55 years and have especially enjoyed building and experimenting with antennas. 73, John

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keith ford
 

Interesting, I will have to save your notes. 

Keith 

On Thursday, February 2, 2017, 13:56, John Adams johnk4qq@... [4sqrp] <4sqrp@...> wrote:

 

I live in an HOA subdivision and am severely restricted with reference to antennas. The 33ft. End fed wire is erected as a sloper running out of an upstairs bedroom to a small tree in the yard. The 33ft. counterpoise runs along the baseboard in the hall. SWR, as measured by the internal tuner in the Kx1 is as follows: 20m, 1.4; 30m, 1.0, 40 m, 1.0. This antenna is recommended by K1YPP who has done extensive portable operation, including walking the AT from Georgia to Maine, making at least one contact from each state. The speaker wire is not desirable as a permanent antenna due to exposure to the elements. I plan on replacing it later with AWG 26 stealth wire and using the speaker wire for portable operation. I have been a ham for 55 years and have especially enjoyed building and experimenting with antennas. 73, John

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