Topband: How Increase 160m power on FL2100z

[Damien F4AZF]

Hi Bill , thanks for reply

On schematic i can observ that on 160m Loading capa is done so : by 3 *
500pf Variable in // "VC2" (the Load button)520pF variable + c31 32 33 34
500pF 3kV in //
So 3500pF total...
And plate capa by C35-36 + VC1 so 250+100+ 120pf variable (who  seems to be
ok here with adjustments.)

Like you tell Bill , that was here the 1st thing that I was thinking about
so add more capacity at Load.

But for the coil around a T200 (I have some here)..so you tell about doing
an "extra longer" "L7" coil I presume ?



In actual summary I notice that :

* I can add some more capacitor at Load on the 160m loading circuit ( I have
some nice 470pf and 1500pF 3.5Kv from LCC)

* I should do a more longer coil L7 at 160 point

I M Right ???

Best 73s thank for help and infos.

Damien f4azf





-----Message d'origine-----
De : Bill & Liz [mailto:magoo at isp.ca] 
Envoyé : dimanche 20 avril 2014 12:27
À : Damien F4AZF
Objet : Re: Topband: How Increase 160m power on FL2100z

Hello Damien-

The FL-2100Z is like many amplifiers where 160M was installed as an attempt
to sell more amplifiers.  You can add some capacitance to the output load
capacitor at the bandswitch and you can also wind up a toroid using a T-200
core and 10 turns of #14 wire on it to be placed on the 160M side of the
tank coil.  It will be a tight fit to make it fit...you can mount it on
thick plastic and glue it to the side of the PA compartment.

Good luck and 73

Bill VE3NH

-----Original Message-----
From: Damien F4AZF
Sent: Sunday, April 20, 2014 5:09 AM
To: 'Tom W8JI' ; topband at contesting.com
Subject: Re: Topband: How Increase 160m power on FL2100z

Hi Tom,

I have ever also have a look few times on your website and infos about the
fl2100, some mods have been also done before I get the PA.

"Load" button on 160m is always at "0" "ccw" even on 1810khz or 1900khz,
just the "plate" get some influence "1" in CW part and "3" at 1850 for
example.

Current IP at 500mA give 400w out on 160m , 700w on 80 and 40m ...
still until 550w on 10m but the PA only used on 160m , sometimes on 80 but
rare.

For 90w IN : 1810Khz 440w          1900Khz 490w          load 0    plate0
at 1810/ 3 at 1900 but 550mA current for this for + 100 good watts in.
So more power on higher frequency on the band.

PA0FRI on his website , on his article about the fl2100z you can read :"The
lower output on the 160 m band is due to the very low Q of the anode
circuit, because the manufacturer has cut the components. The lower power on
the higher bands is due to the decreasing efficiency of the tubes and the
higher circuit losses on the higher frequencies."

But I notice an article also from PA0FRI about an SB200, who has no 160m
band , but he create an extension for 160m band on...

Even if I m technician, I m not comfortable with tubes PA, cause I miss a
bit of practice on... so that's why I ask a bit of help. I ve buy the 2100z
nearly only for the use on the top band SO WOULD LIKE TO PERFORM IT ON 160M
.


Best 73s and thanks also to 3 other Hams sending me direct emails.

Damien f4azf





-----Message d'origine-----
De : Tom W8JI [mailto:w8ji at w8ji.com]
Envoyé : dimanche 20 avril 2014 01:48
À : Damien F4AZF; topband at contesting.com Objet : Re: Topband: How Increase
160m power on FL2100z

>
> I think we must do something on the anode coil for better Q or add 
> some length, change diameter?.. or other things ..?!
>

The only real tank circuit  issue is range of the tank components used to
adjust the matching. Some amplifiers run outside optimum capacitor
adjustment ranges.

Are any of the capacitors bottomed out? Is the load all the way at full
mesh? What is the grid and plate current compared to other bands?


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