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how to modify a serio ??

1iwilly

Sr. Member
Dec 7, 2008
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looking for an open mind thinking can I take my Serio 2016 5/8 wave covers from=26.4 to 28.2 Mhz it's 20.01312 ft tall I want to modify it for HF possibly 40 to 10 the 10-meter band is there now I need the rest need to change. possible base coil needs to be modified need advice as to where to start
 

Your best bet is to leave it alone and one of these if you want a vertical. I say this because if you need to ask how, than you are likely not able to understand the complexities of a multiband trapped antenna. In the end, you will end up ruining the Serio.


Hygain 5BTV
 
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looking for an open mind thinking can I take my Serio 2016 5/8 wave covers from=26.4 to 28.2 Mhz it's 20.01312 ft tall I want to modify it for HF possibly 40 to 10 the 10-meter band is there now I need the rest need to change. possible base coil needs to be modified need advice as to where to start
Not really feasible. Start by getting an antenna that will work the bands you intend to operate.
 
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Your best bet is to leave it alone and one of these if you want a vertical. I say this because if you need to ask how, than you are likely not able to understand the complexities of a multiband trapped antenna. In the end, you will end up ruining the Serio.


Hygain 5BTV
isn't that what being a ham is all about building modifying breaking it fixing it again I have no use for it on the CB band where I live if you don't have 5000 watts for a driver you just be watching your CB like a sony tv
 
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isn't that being a ham is all about building modifying breaking it fixing it again I have no use for it on the CB band where I live if you don't have 5000 watts for a driver you just be watching your CB like a sony tv

Well to be honest you did NOT say you did not have any use for it on the CB band. You should get a copy of the ARRL Antenna Handbook. It contains all the info you need to make your own traps and has some examples of multiband trapped verticals. How you implement them into the tubing is up to you and your construction skills.
 

Well to be honest you did NOT say you did not have any use for it on the CB band. You should get a copy of the ARRL Antenna Handbook. It contains all the info you need to make your own traps and has some examples of multiband trapped verticals. How you implement them into the tubing is up to you and your construction skills.
thanks
 
Look at the DX Commander antenna. 6 band vertical 40 thru 10 meters in one package for around 5 bills or build your own.
 
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looking for an open mind thinking can I take my Serio 2016 5/8 wave covers from=26.4 to 28.2 Mhz it's 20.01312 ft tall I want to modify it for HF possibly 40 to 10 the 10-meter band is there now I need the rest need to change. possible base coil needs to be modified need advice as to where to start
No you can’t. If you want to cover 40 to 10 meters with such an antenna, better use an external antenna tuner. If not, better buy or fabricate an antenna to cover those frequencies.
 
i am no expert on multi band vertical ,but i believe there is a trapless variety ..that are available in the UK..i have one from some stuff i get from a SK ..thay are just a 11m silver rod 1/2 wave or a fiberglass a bit like a A99 with a UNUN at the bottom.. i suppose the taped coil at the bottom of your sirio could be removed and replaced with the correct UNUN ..the one i have i still have the bottom of the box with the UNUN in it when i check for water ingress as i want some stainless screws ..i can photograph it if any one is interested ..this is the one i have https://moonrakeronline.com/gpa-80-hf-vertical-80-6m-no-gaps-no-radials-perfect-swr-with-at
 
After looking at several pictures of the Sirio 2016 loading coil online, it appears to be tapped at about the same point as the Sirio 827. It is an L-Network. From the coax connector's perspective, there is an inductor to ground and an inductor inline with the vertical element.

With the vertical already having a matching network, attempting to load the antenna at a different frequency will be more difficult than it would be without the built-in matching network since there is a fixed inductor to ground.

I think the only way to do it is to disconnect the loading coil from ground (which is inside that waterproofing coil cover) and to use a tuner. The top half of the loading coil would stay in series with the antenna, but the lower half from the tap point down would not be connected to anything.

This does mess up both the tuning for 11m and the DC grounding it had, but both problems could be solved with a tuner at the other end of the coax (although it depends on tuner style for the latter). If it is a typical high pass T-tuner, then a 10k resistor capable of handling the expected voltage could be used to return the antenna to DC ground for static discharge purposes.

With the coil modification, there will be a mismatch at the antenna connector, even at 11m, so this means the length of the coax will have an impact on the tuners ability to match a given frequency as the coax is acting as a frequency dependent impedance transformer. It should not affect the SWR, but the length will have a significant impact on the range of impedances seen by the indoor tuner.

That is not a bad thing though. Again, the length of coax is not changing the SWR, it is the complex impedance that changes as it rotates around a constant SWR circle, so, if you find that on a particular band the tuner cannot obtain a match, simply adding a piece of coax can move the impedance to something the tuner can handle. This is a case where a mismatch at the antenna is a benefit.

The other option is to create a new mounting bracket that can accommodate the ground radials and allow you to isolate the existing mount and unused radial hub from ground. You could then drive the antenna from the bottom end of the loading coil where the ground was (ignoring the existing connector and tap point) and run the entire loading coil in series with the vertical element.
 
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Just got the Comet CHA 250 BX for 80 to 6 meter it will do 160 and 4 meter as well.
Not expecting much of he 24 foot radiator on 80 and 160 though.
I do have dedicated antena's for that though.
Just a fun vertical that works fine on 10/11/12/15 and 17, rest of he bands is bonus.
adding 4 radials to it on the roof of 26 feet.
 

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