[DCboatanchors] [MOPAGROUP] 50.3Mhz CW project:: 5-10Watts but I can not "listen" to the signal on the freq.

[Bry Carling]

Wow - what a fantastic-sounding (and SIMPLE) tube transmitter!

I would love to see it in action, or hear it on the air!

Congratulations, Anibal!

On 24 Aug 2010 at 19:38, Anibal  
hk3arr at gmail.com wrote:

> Hi experts!
> This project has been taking me a lot of time, mainly because this
> is the way i am learning to work with tubes. I will appreciate all
> the help, I am doing my best in order to explain as clear as
> possible, i hope you will understand!, here I go:
> 
> I have already finished one project: "50.3Mhz Beacon (cw)". This
> involve the following sections / tubes:
> 
> Oscillator:
> Triode/pentode ECL80. I built this section according to this project
> (thanks to Brian!!):
> http://s88932719.onlinehome.us/ham/ecl80.htm
> 
> Driver:
> I use a EC80 as a "extra driver" cause the pentode in the oscillator
> already act as a Driver, am I right?
> 
> Powe Amp +  Pi network
> I am using 2 x 6DQ6B tubes so this is the final setup:
> 
> ECL80 >>TRIMPOT at the gate (50K) >>EC80>> TRIMPOT at the gate (50K)
> >> 2 X 6DQ6B >> PI NET >> LOAD
> 
> This is the current situation: I dont have any spectrum analizer or
> any other special gear to measure signal so what I am doing is
> placing a "piece of cable to act as an antenna" in diferent stages,
> then I am able to "listen" with one of my radios to the following
> signals:
> 
> 1- I have placed the "antenna" at the Triode plate (ecl80) and i can
> listen to the "oscillator signal".
> 2- I have placed the "antenna" at the pentode plate (ecl80) and i
> can listen the "oscillator signal" --> with higher level than the
> triode
> 3- I have placed the "antenna" at the triode plate (EC80) and i can
> listen the "oscillator signal"   --> with higher level than the
> pentode.
> 
> So far all seems to be ok. Lets go to the P:A + Pi Net:
> Power Amp Stage: I start to manipulate the pi Network in order to
> give proper Imp match, I can notice about 5 to 10 Watts on the
> Wattmeter but "i can not notice any signal on the frequency". Any
> idea why these tubes could send a 5-10 watts signal which is not
> located on 50.3Mhz?
> What should I check?
> 
> All help is more than welcome!
> 
> Br
> 
> Anibal
> Hk3arr, yv5arr
> 
> 
> 
> 
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