Homebrewing a Sirio Gainmaster using RG58 and 2.5mm wire.

[adrian]

I wonder how many people have made one of these gainmasters? and have not actually mentioned it.
I made one up yesterday,after receiving westflex 103 via a propper courier,,in other words it got here in one piece.
only problem i had was the connection of the matching stub , a little bit of a pain to do.Needed some heat on that thick coax!!!
swr is 1.7. not bad for a starting point!.swings about in the breeze quite nicely.
Also noticed less static,in other words the s7 of rubbish has gone!
A big thankyou to the peeps who done all the leg work and all the calculations, :-)
ADE

[caketin]

Hi does anyone have the hi res piccys of the build that PsiDOC created for the gain master?
The links are dead and was interested in the build.
If anyone could help, it would be appreciated

caketin

[kamikazeandi]

Hello,
I've modified the dimensions of my last 2 GM a bit. I built them for 2 HAM-friends. I built all coax-parts with RG-213. The upper radiator is made of flexible Cu-Wire with PVC-isolation. The dimensions for best SWR for me were at the end of testing (with "MY" RG-213):

GainMaster-Construction_RG-58_RG-213_en.gif

And I've turned the choke 90°, so that the RG-213 "flows" more smoothly in the choke as you can see below (grey = GFK-Mast & black = GM):

GainMaster am Mast.gif

Hope that helps a bit to build one yourself with RG-213.

kamikazeandi

[teoneo]

Thank You Andi ! When i do my own ,I will tell how it works

[teoneo]

Hi Guys !
My SWR is 1.2 on 26 MHz and 1.6 on 30 MHz . Thanks for all 73

[CBCharlieST]

Hi Guys,
In front of us is a new challenge! Gain Master half wave 5560 mm or 11.2 feet.

http://www.sirioantenne.it/hf-base/gainmaster-hw/

[43cs44]

I think they posted their dimensions wrong, My calculator says 5560mm = 18.24 feet .
Think "Half wave flowerpot antenna" built for 27 megs

[transit2500]

bringing this back up . i made one this week but swr will not come down2.5 i dont understand the capacitor i have done the 25mm then took braid away then from the top one up 10mm and took some braid away to for a tag then i connected to that the top wire .everything i have done as in the aticle can some one show me how to do the capacitor 8.3pf whick mst be the 10mm bt i could be wrong.... up date re worked capacitor after somone showed me how to make one just got to put it up today and tune

[Kaos]

I wonder how many people have made one of these gainmasters? and have not actually mentioned it.
I made one up yesterday,after receiving westflex 103 via a propper courier,,in other words it got here in one piece.
only problem i had was the connection of the matching stub , a little bit of a pain to do.Needed some heat on that thick coax!!!
swr is 1.7. not bad for a starting point!.swings about in the breeze quite nicely.
Also noticed less static,in other words the s7 of rubbish has gone!
A big thankyou to the peeps who done all the leg work and all the calculations, :-)
ADE

I got round that by using PL plug T-pieces. Less work and easier to put up n take down.

Noise floor dead and 25 to 30 Mhz Swr is in green working range.

[Nasa]

If you need more input you may check out this forum web site:

https://funkbasis.de/viewtopic.php?f=15 ... &start=690

There are a lot of pictures and diagrams regarding DIY Gain-Master.
Discussion is in german but english posts will be answered and welcome as well.

Regards,
Lothar

[PsiDOC]

MY goodness.
Is this thread still alive?
I am humbled.

[MrWeetabix]

Can I just thank all the contributors to this thread. This is exactly why TM1 is here, to provide information, guidance and support for other hobbyists.

This information would be pretty much lost on a social media platform or on a chat board, but this thread will be searchable on this forum, and therefore via google, for (hopefully) many years to come, allowing those whom follow us into this hobby to recreate this fantastic project and get some real enjoyment and satisfaction from their hobby.

So again, I thank you all. You guys are what makes this forum so good.

[bigal68]

Hi PsiDOC,

Nice to see from you again.

I've built 3 "PsiDOC" Gainmasters now, and my original one I made in 2013ish is still doing sterling business.

I would just like to thank you for the original work you did at the beginning of this thread.

Top man.

[Maslasse]

Hello PsiDoc.
Yes it's alive and hopefully it will go on. Just finished my first build of GM with RG-174 for a test. Got SWR 1,5 at 25Mhz 1,2 mid 27Mhz and 1,9 at 30Mhz. Have only tried it with abaut 15-20 Watt so far. Try to set Ferrit Toroids instead of airwounded choke. 8 Turns on toroid 240-43 hopefully it will reduce heat with Hi-Power.

[Maslasse]

Hello PsiDOC and the rest of U all.
Have read all the posts here. Thanks for a awesome info about the build of the Gainmaster. Followed the instructions from it and now
is my homebrewed GM on a woodenpol with the top on 7 meters. Looks nice indeed with the SWR and the broadband of the antenna.
Gone do more test this weekend when the radio arrives. Got to changes the top radiator from innercondutor from 75ohms TV to 1.5mm
standard wire.
It's made of RG-174 with a 50mm choke with 12 turns, didn't have sufficient lenght of RG-174. Seems to work OK.
Best regards to you all in the group.