LF: RE: Re: RE: MORE VALVES

["Ken" <ken.h.wright@btinternet.com>]

Hi Mal. Thanks for the info, in my younger days as an electrical engineer occasionally had to work on live bus-bars so know the dangers, one of use got very badly burnt one day. I am still not clear regarding the NoV for 472kHz, I would have thought that if approved by WRAC then NoVs would not be required. I will try to improve my cw and meet you on the new band soon, I do enjoy cw although not very quick, at present I am using an RAF ‘D’ type, have tried a double paddle keyer not much success, am going to try a single paddle, what would you recommend?

 

73s.

 

Ken

 

M0KHW

 

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From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of mal hamilton
Sent: 19 December 2012 22:25
To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: RE: MORE VALVES

 

Ken

The valve and base in the picture is a 4CX1500B  that was intended for 137 Khz not 500 Khz.

At present both on 137 es 500 I am using solid state Transmitters, which are probably safer. I do have a selection of Dentron Amplifiers for the HF Bands with 8875 valves.

Watch those High Voltages, no margin for mistakes, one Wobble and you Vaporise !!

73 es GL de Mal/G3KEV

 

 

----- Original Message -----

From: Ken

To: rsgb_lf_group@blacksheep.org

Sent: Wednesday, December 19, 2012 8:20 PM

Subject: LF: RE: MORE VALVES

 

Hi Mal.

What valve are you using? I am currently building a TX with a 6293 Beam Tetrode in the PA. the building of the two power units has slowed the construction down with the inter-linking control cables etc. The PA xformer is 650 – 0 - 650 volts @ 400mA with a bridge rectifier, the valve max anode voltage is 3Kv and anode current 1.5A. I am hoping for Class C, 500 watts output cw on 472kHz (if we ever get the NoV).

 

73.

 

Ken

 

M0KHW

 

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From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of mal Hamilton-Sent: 19 December 2012 09:39
To: rsgb
Subject: LF: MORE VALVES

 

This is a 137 Class C amp project, but since CW activity  has dropped to virtually NIL I am not rushing to complete.

de G3KEV