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Re: [Amps] Amps Digest, Vol 101, Issue 33

To: amps@contesting.com
Subject: Re: [Amps] Amps Digest, Vol 101, Issue 33
From: K3vw@aol.com
Date: Mon, 23 May 2011 18:34:16 EDT
List-post: <amps@contesting.com">mailto:amps@contesting.com>
Carey, the GS-35B tube is NOT a high mu triode. It is a medium mu triode  
the requires a very well built, input circuit, for the "flywheel" effect. 
More  plate voltage will also lesson drive requirements. It is a MEDIUM MU 
triode, not  to be compared with an 8877.
 
K3VW-Vaughn  "Willy" Worth, Sr.
In a message dated 5/23/2011 3:00:23 P.M. Eastern Daylight  Time, 
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Today's Topics:

1. Re: load resistor  (Carey Lockhart, KC5GTT)
2. arrrrgggg!! (Carey Lockhart,  KC5GTT)
3. Re: arrrrgggg!! (TexasRF@aol.com)
4. Re: arrrrgggg!! (Carl)
5. Get access to my pictures and  more (Shon Edwards)
6. Re: arrrrgggg!! (Steve  Thompson)
7. Re: Get access to my pictures and more (Peter  Frenning [OZ1PIF])
8. Re: Get access to my pictures and more  (Shon  Edwards)


----------------------------------------------------------------------

Message:  1
Date: Sun, 22 May 2011 14:49:05 -0500
From: "Carey Lockhart, KC5GTT"  <kc5gtt@gmail.com>
Subject: Re: [Amps] load resistor
To:  <TexasRF@aol.com>,  <amps@contesting.com>
Message-ID:  <6E51FE3972F84985B4F36A6E4F18B54D@careychbqjio7i>
Content-Type:  text/plain;   charset="iso-8859-1"

thanks very much for that  info. it is most usefull. i having tons of fun 
building the amps. sadly in my  20 years of being a ham there is still so 
much i still have to  learn.

Carey, kc5gtt
----- Original Message ----- 
From: TexasRF@aol.com 
To: kc5gtt@gmail.com ; amps@contesting.com  
Sent: Sunday, May 22, 2011 11:10 AM
Subject: Re: [Amps]  load resistor


Carey, you can confirm resonance with the  plate tuning capacitor. If you 
see a peak in output power while adjusting the  control, there is resonance.

A slight increase in C will lower  the frequency of resonance and the power 
will drop. A slight decrease in C  will raise the frequency of resonance 
and the power will also  drop.

The plate loading can be confirmed in a similar manner.  Maximum power 
output happens with optimum load C. When the load C is adjusted  up or down in 
value and the plate tune is adjusted for resonance, the power  output will 
drop relative to the optimum load C adjustment.

As  load C is increased in value, the plate load impedance is lowered and 
there  will be a resulting increase in plate current.

Strip line  designs are not noted for having highest efficiency. The 
primary cause of this  is unequal rf currents flowing between the strip line 
and 
various parts of the  tube anode connection. The strip line is basically 
connected to about 1/3 of  the tube anode and the other 2/3 of the anode has 
very little current  flow.

There are losses in all parts of the plate circuit,  including the anode 
cooler where it connects to the strip line. If most of the  current flows in 
1/3 of the area, two things happen: 1> the loss resistance  is 3X and 2> the 
rf current in this area is also 3X.

Loss  being related to current squared times resistance, then the total 
loss becomes  3X3X3 or 27 times greater than a truly balanced anode to 
resonator rf current  flow. What could be a low loss of say 10 watts, quickly 
becomes a 270 watt  loss and this shows up as lower power output and efficiency.

The  designs using parallel resonators, such as the W6PO design, will have 
far  better rf current balance and associated power output and efficiency. A 
 cylindrical coaxial resonator design is the best of all but few 2m designs 
 have been published. A coaxial resonator for 144 MHz is not  small!

There are a number of 2m GS35B amplifiers documented at  
www.nd2x.net/base-1.html if you haven't been there. Operating conditions are  
shown and you 
can compare your results.

Others have mentioned  the measurement accuracy of both the dc metering and 
rf output power. These  factors can cover quite a range of performance 
discrepancy. It may well be  that your amplifier is working as well as it ever 
can!

73,
Gerald K5GW







In a message  dated 5/22/2011 9:42:25 A.M. Central Daylight Time, 
kc5gtt@gmail.com  writes:
Hey guys,

before i fire my amp  back up i think i need to check the stripline 
resonance. i have 4100 volts on  the plate of the gs35. what formula should i 
use 
to come with a resistor  value?

or am i going about it wrong. it was working  before but not like it 
should. i had very poor efficency. which we have more  than covered HI. any 
suggestions? at that voltage 1500 out with 100 watts  drive was a reach. i feel 
i 
should be able to get that with much less drive. i  just dont know where to 
start

Carey, kc5gtt
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------------------------------

Message:  2
Date: Sun, 22 May 2011 22:19:12 -0500
From: "Carey Lockhart, KC5GTT"  <kc5gtt@gmail.com>
Subject: [Amps] arrrrgggg!!
To:  <amps@contesting.com>
Message-ID:  <BB90496446AA4FBB91CF0ABFE3961ED1@careychbqjio7i>
Content-Type:  text/plain;   charset="iso-8859-1"

ok guys i have the amp  back together in the yu1aw lazy builder. now i am 
getting much lower efficent  

plate 3400 full load
current 1.2a
drive 100w
output according  to my cheap meter 1600 and my other cheap meter 1900

eff. around  35%

now i am wondering how to determin actual output from these values.  is 
there a way? also is the flapper capacitor a bad way to go?  

Carey

------------------------------

Message: 3
Date:  Mon, 23 May 2011 08:16:58 EDT
From: TexasRF@aol.com
Subject: Re: [Amps]  arrrrgggg!!
To: kc5gtt@gmail.com, amps@contesting.com
Message-ID:  <5c8a.631b9679.3b0baa3a@aol.com>
Content-Type: text/plain;  charset="US-ASCII"

Hi Carey, flapper tuning is the best (maybe only)  method for resonating a  
strip line plate circuit.

There are  always losses in these circuits due to unavoidable resistance in 
 
the  metal parts and rf currents flowing through them.

For the lowest loss,  highly conductive metal, such as copper, is used.  
Brass is often  used but the inherent resistive losses are much higher than 
 
copper  unless the brass is silver plated.

Losses are related to rf current  squared. Using the minimum possible 
tuning 
C will correspond to minimum rf  current. The flapper should have a wide 
spacing  at the strip line  and be well grounded at the cold end. The wider 
the 
spacing,  the  lower the C and resulting rf current. If the flapper is too 
closely  spaced,  the strip line length is too short.

The rf field around  the strip line is very intense at the power levels  
involved here. It  is important for all metal joints in the strip line and 
the   
enclosure be rf tight. Lots of screws are needed and everything has to be  
clean  and tight. Screw spacing of 2 inches is not  excessive.

Your figures of 3400 volts and 1.2 Amps yield a dc input  power of 4080  
watts. If the output power is 1900 watts, that is 45%  plate efficiency 
ignoring 
feed through power. The actual power output may  well be higher and a 
better  calibrated wattmeter will tell. Maybe a  friend can loan you one 
for a 
test. 

73,
Gerald  K5GW







In a message dated 5/22/2011 10:19:26 P.M.  Central Daylight Time,  
kc5gtt@gmail.com writes:

ok guys   i have the amp back together in the yu1aw lazy builder. now i am 
getting  much  lower efficent 

plate 3400 full load
current  1.2a
drive  100w
output according to my cheap meter 1600 and my  other cheap meter  1900

eff. around 35%

now i am wondering  how to determin actual  output from these values. is 
there a way?  also is the flapper capacitor a bad  way to go?   

Carey
_______________________________________________
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http://lists.contesting.com/mailman/listinfo/amps



------------------------------

Message:  4
Date: Mon, 23 May 2011 09:16:24 -0400
From: "Carl"  <km1h@jeremy.mv.com>
Subject: Re: [Amps] arrrrgggg!!
To:  <TexasRF@aol.com>,  <kc5gtt@gmail.com>,  <amps@contesting.com>
Message-ID:  <5C7B89692E2248FDB68F22435C7C10F1@computer1>
Content-Type:  text/plain; format=flowed; charset="iso-8859-1";
reply-type=original


----- Original Message ----- 
From:  <TexasRF@aol.com>
To: <kc5gtt@gmail.com>;  <amps@contesting.com>
Sent: Monday, May 23, 2011 8:16 AM
Subject:  Re: [Amps] arrrrgggg!!


> Hi Carey, flapper tuning is the best  (maybe only) method for resonating a
> strip line plate  circuit.

Its not the only method Gerald, I use a small vacuum variable;  never did 
care for the mechanical problems of a flapper. Im also using the  split 
line  
tank.

Carl
KM1H




------------------------------

Message:  5
Date: Mon, 23 May 2011 16:08:16 +0000
From: Shon Edwards  <noreply+A73169060@netlogmail.com>
Subject: [Amps] Get access to my  pictures and more
To: <amps@contesting.com>
Message-ID:  <19.F3.04202.DB38ADD4@mail03>
Content-Type: text/plain;  charset=utf-8

Hey,

I have created a Netlog profile with my  pictures, videos, blogs and events 
and I want to add you as a friend so you  can see it. You first need to 
register on Netlog! When you log in, you can  create your own profile.

Take a  look:
http://en.netlog.com/go/mailurl/-bT0xODAyMjQ4ODkxJmw9MSZnbT0xMiZ1PSUyRmdvJTJ
GcmVnaXN0ZXIlMkZpZCUzRC1ZVzF3YzBCamIyNTBaWE4wYVc1bkxtTnZiUV9fJTI2dWlkJTNEMTY
1NTQzNTI2

Cheers,
Shon

----------------------------------------------------------------
Don't  want to receive invitations from your friends  anymore?
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lMjZjb2RlJTNEMTU1NDE1Mzg_


------------------------------

Message:  6
Date: Mon, 23 May 2011 17:22:36 +0100
From: Steve Thompson  <g8gsq72@gmail.com>
Subject: Re: [Amps] arrrrgggg!!
To:  amps@contesting.com
Message-ID:  <4DDA89CC.3050106@gmail.com>
Content-Type: text/plain;  charset=ISO-8859-1; format=flowed

> Hi Carey, flapper tuning is the  best (maybe only) method for resonating a
> strip line plate  circuit.
>

I think Carey said he was using the YU1AW 'lazy  builder' circuit. That's 
not the usual resonant stripline with capacitive  coupling design. 
Visualising it on Smith chart is the easiest way for me  to think about 
how it works. Probably long before YU1AW, N1BUG built a  4CX1000 amp that 
way, with stripline instead of the lumped inductor YU1AW  uses.

Carey - what value capacitors are you using, and what are they  set to at 
max. output. Some pictures might help. The series one at the  output 
connector is like a loading control. The figures you mention  suggest 
that the anode impedance is too low. Less capacitance should give  you a 
higher anode load impedance, and thus better efficiency - but if the  L 
and other C aren't right you might never be able to hit a pure resistive  
anode load and things won't come  right.

Steve


------------------------------

Message:  7
Date: Mon, 23 May 2011 20:03:49 +0200
From: "Peter Frenning [OZ1PIF]"  <peter@frenning.dk>
Subject: Re: [Amps] Get access to my pictures and  more
To: Shon Edwards <sre.1966@gmail.com>
Cc:  amps@contesting.com, Shon Edwards
<noreply+A73169060@netlogmail.com>
Message-ID:  <4DDAA185.7020206@frenning.dk>
Content-Type: text/plain;  charset="ISO-8859-10"



------------------------------

Message:  8
Date: Mon, 23 May 2011 12:23:25 -0600
From: Shon Edwards  <sre.1966@gmail.com>
Subject: Re: [Amps] Get access to my pictures  and more
To: "Peter Frenning [OZ1PIF]" <peter@frenning.dk>
Cc:  amps@contesting.com, Discussions of Antennas and Related Topics
<antenna-discussion@antennex.com>,  antennaware@contesting.com
Message-ID:  <BANLkTi=kDi8ghCDovd-2RHc7pF93awLmoQ@mail.gmail.com>
Content-Type:  text/plain; charset=UTF-8

Sorry all!  Someone apparently hacked  into my account and sent a message to
everyone in my gmail account.  I  do apologize for the inconvenience.  I 
have
had this happen once  before and it is not very fun!

2011/5/23 Peter Frenning [OZ1PIF]  <peter@frenning.dk>

> Den 23-05-2011 18:08, Shon Edwards  skrev:
>
> Hey,
>
> I have created a Netlog profile  with my pictures, videos, blogs and 
events and I want to add you as a friend  so you can see it. You first need to 
register on Netlog! When you log in, you  can create your own profile.
>
> Take a  
look:http://en.netlog.com/go/mailurl/-bT0xODAyMjQ4ODkxJmw9MSZnbT0xMiZ1PSUyRmdvJTJGcmVnaXN0ZXIlMkZpZCUzRC1ZVzF3YzBCamIyNTBaWE4wYVc1bkxtTnZiUV9f
JTI2dWlkJTNEMTY1NTQzNTI2
>
>  Cheers,
> Shon
>
>  ----------------------------------------------------------------
> Don't  want to receive invitations from your friends  
anymore?http://en.netlog.com/go/mailurl/-bT0xODAyMjQ4ODkxJmw9MiZnbT0xMiZ1PSUyRmdvJTJGbm9tYWlscyU
yRmludml0ZSUyRmVtYWlsJTNELVlXMXdjMEJqYjI1MFpYTjBhVzVuTG1OdmJRX18lMjZjb2RlJTN
EMTU1NDE1Mzg_
>  _______________________________________________
> Amps mailing  
listAmps@contesting.comhttp://lists.contesting.com/mailman/listinfo/amps
>
>  More spam - stay away!
>
> --
> Vy 73 de OZ1PIF/5Q2M,  Peter
>
> *****************************************
> **  Genius is one per cent inspiration, **
> ** and ninety-nine per  cent            **
> **  perspiration.                   **
> **             -- Thomas A. Edison   **
>  *****************************************
> email: peter(no-spam  filler)@frenning.dkhttp://www.frenning.dk/oz1pif.htm
> Ph. +45 4619  3239
> Snailmail:
> Peter Frenning
> Ternevej 23
>  DK-4130 Viby Sj.
> Denmark
>  *****************************************
>
>
>


--  
Shon R. Edwards,
Amateur call:  K6QT
1039 N 2575 W
Layton,  UT, 84041-7709
USA
e-mail:  sre.1966@gmail.com
phone:   (801) 444-3445
cell:  (801)  336-7635


------------------------------

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End  of Amps Digest, Vol 101, Issue  33
*************************************


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