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HOMEBREW that lineer "ElCheapo"

HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Tue Apr 19, 2011 9:19 pm

I am interested in building a project "with other hams" ..wishing to build a small 400watt or less all band lineer, even if to be their first, i have done a few in the past.
I will be starting a small lineer all bands soon., so if their is interest ,,,post here so we know who are interested, and then we can do it in steps together.
\
"starting: with parts is parts"

johan zs2cx
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Re: HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Tue Apr 19, 2011 9:28 pm

Alex..1L now's \the right time, when are u starting your plankie lineer :lol:

i will post some ugly pans and starter stuff 2 morrow, step by step building.

"roll your own or start to moan" :P
they dont come cheap, new at 10 to 15 bucks a watt...

...or homebrew at a buck a watt :evil: and it can become an obsession...
CROC :evil:

Save this fav link, it will come in usefull, u can bet on it.

http://www.scottbecker.net/tube/sheetsV.html
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Re: HOMEBREW that lineer "ElCheapo"

Postby V51Q » Wed Apr 20, 2011 8:05 pm

:twisted: My lil amp...! :twisted:

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Re: HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Wed Apr 20, 2011 9:57 pm

Jeez ,Mike
dinamite, comes in small packages.

TOY2- in Progress 2010
Image

DONE :twisted:
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But 1 of the many toys, Mike :geek:
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Re: HOMEBREW that lineer "ElCheapo"

Postby V51JP » Wed Apr 20, 2011 9:58 pm

kikass paint job :twisted:
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Re: HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Wed Apr 20, 2011 10:24 pm

Wee bit more than ass
go see qrz.com
the titans up there, and the store room has some more toys. once done it goes in storage :roll:
croc :mrgreen:
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Re: HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Mon Apr 25, 2011 10:26 am

I might be gone for a day or 2, but here's the circuit for a small amp i have build in various tube combo's.
With slight change of voltage requirements for filaments or HT suiting the tube, the circuit is basic, the same.
C5 and 4 will be juiced up to 5 or 6 kv, with c5 we will use a doorknob capacitor for the higher current of say a 813 tube.
Up to 350 watt the yellow peppermint cap will do with normal ssb operations.

Image

Most of the low power amplifier parts are locally available, well actually all of them, depending on how intensivly u search.
the most valuable parts is the transformers and your antenna relay :roll:
well that goes for the band switch as well, i used a small multi switch from http://www.electronics123.co.za
they have a couple of them if u have a problem with high value variable caps , buy the 2 waver option so u can switch in a 100pf fixed cap to the band where u need some more capacitance.(see my 160m band extra switch on sketch)

The 2.5 mH inductor is 4cm long pink or brown in colour, if the dc blocking cap goes s/s or open the ht will follow the circuit to the 2.5mH choke and trip the circuitbreaker, or blow your fuse in the circuit, preventing nasty things from happening.
U can roll your own ( 7 to 9 ohm choke as well with thin wire, enough thickness to blow the fuse)0.3mm will do fine.

Construction starts with laying out the parts on your amplifier pan, then mount the transformers and base, do the psu wiring, get your psu going and test it.
once tested mount your tube and test the filaments, then add a 110v transformer to the ht primary side, to fire it up on halve the voltage say 700v or so, just to bring the old tube up slowly to hv voltage...
if all goes well we can apply full ht voltage in a few minutes.
So the psu is working and the tube or tubes are functioning well :mrgreen: i feel good today :mrgreen:

now we start with the tank circuit layout as planned, mount all and select taps as required, wire the antenna relay and test it, without amplifier ht online. If all works continue to neaten up the wires, do not fasten as a permanent install, we might have to change some stuff, transformers etc..
---------make up a 5cm long croc clip wire-----
Ok... :twisted:
:!: NB:
1.remove all power from the circuits
2.Solder a 2.7k resistor (JUST AFTER PC1) and before C5 to earth.
3. lock the antenna relay in Tx mode (small external psu) or push it by hand when needed,( u will see :roll: )
nb: 4.connect your Mfj 269 TO THE ANTENNA PORT.
5. ADJUST THE MFJ TO 80M PORTION 3.750 etc.
6.attatch your croclip to 80m bandswitch and where u think 80m might be on the tank inductor, push the antenna relay, adjust the croclip untill u find the best tap 50 ohm xs-0 or close.(maybe rs49- xs4 :twisted: all ok....
7. move on do the rest of the bands.( remember the antenna relay to be on tx while adjusting the bands on the inductor
when done ...
start the amp for testing, let it idle a minute, move your variable caps throught 180 degree rotation, watch your amp meter for fluctuation, indicating a possible runaway :o
check all bands.I used a 2 amp fuse on the 220v just for incase(with the 811a amp)
IF all checks out fine, test thye creation on a dummyload.
Now we fire on a antenna of choice, make notes of adjustment and enjoy our creation of power.
:twisted:
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Re: HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Tue Apr 26, 2011 11:26 am

now i am off to the garage to take some sample pics, of what we need :lol:
then i can post a pictured listing. :P
well that would have helped me when i started out!
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Re: HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Tue Apr 26, 2011 5:26 pm

This is most of the parts i will use, now packed away until D day.

Image

i am still searching for a smaller antenna relay as the one in the photo is good for a few kilowatt and we really need a 200 watt jobbie. :roll:
Dont be shy now, u can do it... :mrgreen:
Like all projects if u start this one, be carfull that little ht transformer and the small ones pack 220v and 1000v rectified = 1400v at 200ma :!:

...................................................................
....Always.....
Rules is Rules
one hand behind your back.
or in the pocket :lol:
use a chicken stick.
mains off means disconnected from 220v ac.
Dont trust your bleeder resistors, rely on the chicken stick and bleed the system to ZERO volts.

{When doing 220v wiring watch out for wire errors in panel lights, effectively giving the systen 110v when wired incorrectly.
that means 750v ac on the HT side :!: }
Even switches fail: wire the 220v so that u need to flick a second switch to power on the HT(first switch lights filaments and supplies second switch with power for the HT transformer)
Work on a thick rubber mat.

"This counts for any would be constructor" me included :twisted:
There might be more, but is all i can think of now.
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Re: HOMEBREW that lineer "ElCheapo"

Postby zs2cx » Fri Apr 29, 2011 10:13 pm

I got some much needed help, today
...of coarse they were up to mischief as always, so dad helped them out a bit...

Image

the inductor is meant for the amp project 160m part, enough for 2, so i wont have to do it again soon.
i need to make a 50mm Diameter part as well for 40m to 15m and then a 3 turn coil for 10m.
Ronan and his buddies were pestering all they can in the yard so we got them in a tug of war with the 2.5mm copper wire :mrgreen:
They drew a good 128kg on a scale :mrgreen: , once the wire was heated and cooled down again the boys stretch it a bit and then i made them pull it after each turn :roll:
So they are sleeping early tonight :D
Here's a bigger pic
Image

GHMFF...that will teach them to take me on....
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