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Don Dulmage
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VE3LYX Ham Since 1980

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Other Callsigns
First issued VE3LYU

My Ham Radio Interests
Homebrew tubes CW and AM. Minimalist style.
Skeds for low power QSOs with homebrew stuff.

50C6 Cw rockbound with matching 12sn7 regen.
01 TNT 40M with matching 01 regen
40M hartley CW
80M x 40M Am transceiver HB
Two No 19 Wireless Sets
6l6 Breadboard Cw TX and matching 6sl7 regen.
BC454 recvr Operational 80M
ARC 5 T18 transmitter which now covers all of 80M band in CW and AM (cathode modulated through CW key jack)
Twin 811A HB linear Amp.

Other Interests
Speak Deutsch at a functional level, can get by in French but it is hardwork for me.
Make fiddles and play them. (gospel and country)
Drag racer . I run The Senior Dragster. Slant six powered.
I race it at Picton Airfield
Am a writer. I have two books published and many magazine articles in both the USA and Canada. I used to have my own opinion column in a local paper for several years.(View from the Ridge)
Cast aluminum for fun.
Also raised cattle for several years and trucked them. I also bought and sold for others. (Dolmetsch Beef Farm)

In the interest of allowing others to enjoy their clubs I now refrain from joining.(does not play well with others)

Supressor grid modulation rig


3/12/2014 4:41:00 AM (0 comments) Add a commentAdd Comment

A few years back after I returned to this hobby seriously after a few years of backburner activity I experimented with several types of modulation. So far I have done a screen modulated rig several times, loop modulated from the 1917s, collector current modulation, several variations of cathode modulation and a project I started back then using suppressor grid modulation. This project was loosely based on the old Lancaster Bomber transmitter, the T1154 and uses the purpose built VT104 (PT215) tube which I bought NOS. I used the training circuit as a basis (only one output tube) Some of the design I did not like being as it was over complicated for no particular reason. This was true especially in the osc circuit so I used my own favourite standby a Hartley instead with a 4 turn link out. After a long bench rest of a year or so I dragged it down yesterday and went back to work on it. By supper time I had the big tube drawing 50 mils at 1200 volts with no hick-ups. I will continue on it today modifying some things as since my return to the hobby seriously I have picked up some understanding and skills I never had before. The more one builds the easier it gets. I now just build without schematics. I didn't think that would ever happen. I would encourage others who are so inclined to do the same. Jump in and build. Commit you favourite circuits to memory. For me the best way of doing that is to build them and play with them till I am happy with it. After a while it becomes almost second nature. Anyway enuf soapbox. I am looking forward to getting this suppressor grid modulated Am transmitter on the air. It is tuned for 40M which should be good. Hopefully this week.

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