sorting out my spare tubes. if anyone needs 55 tubes let me know. send messages direct. Ben

This is a big ongoing project thst is half complete. It involves the following: 1. The top tank tuning capacitor is converted to split stator by using threaded nylon rod to hold the vanes and putting an insulating spacer between the two halves. This allows me to run the two PT15s in push-pull. 2. All tank coils are replaced with new ones for the desired bands 160.80 and 40 and are split in the center and routed through the tank bandswitch to the primary of a big toroid to which the 1250v HT is applied on a center tap. The secondary of the toroid has the lower of the tank tuning capacitors across it and its many taps go to one of the antenna tap switches. This effectively makes a balanced Pi circuit. 3. A big toroid is used to drive both PT15s in push pull between gris and filament, but neither is ground. Instead a tap somewhete grid and filament ends is grounded so operatin is half way between ground grid and grounded cathode. This is multifilar winding to pass heater citrent to both filaments and insert grid bias. The primary of the transformer is a center tapped 2 +2 turns to accept the output of the balanced Pi citcuit of the driver, which is two B5 base 807 copy attempts and replace the VT105 triodes. 4. The modulstor is an I and a Q beam deflection tube, the sum of whose outputs drives the driver grids. The deflection plates take I and Q modulsting signals, which SSB come from a ployphase RC quafrature network. The hrids of the beam deflection tubes are driven by quafrature RF using a wideband LC quadrature network covering 1.75 to 10MHz. 5. Power supply is a 12v transistor Hbridge rnning at 209KHz drivibg a toroid to provide 259v. Venter tap of the primary gives a vobstantv6v for filsments. The 259v secondary dtives a push-pull Cockroft Walton 5 stage rectifier giving 259, 500 and 1250v. Psu is pretty small and fits in a screened box in the back whete the big green resistors were. I will post pictures when complete. Paul

I was the sunday morning net operator in an ATC squadron in the '50s using 1154/1155. I have just always loved these radios,, but they have quirks Here are 2 simple things you can do to an R1155 to improve it: 1. Frequency stability: Replace the ceramic compression trimmers with Johanssons 2. SSB performance is spoiled by AGC pulling the LO. Just take AGC off the mixer tube grid and contrive -3v fixed grid-cathode bias. I did that wirh a 3.3v zener. If you want to do a bit more, I found some very cheap 560KHz ceramic resonators which I used within the existing IF cans to sharpen up the selectivity. I simulated proposed bandpass filter structures in FORTRAN first to get nice flat top to the response of each can. Paul ex-G3VEL now KX4GP

Hi, have just joined the group as I'm in the process of rebuilding a R1155N receiver, and looking for relevant data and documents. Derrick

Hi, have just joined the group as I'm in the process of rebuilding a R1155N receiver, and looking for relevant data and documents. Derrick

Lots of spare time due to shutdown. Made some outer shells for the 8 pin Jones Plugs. Started with thin aluminum from beer cans to make the patterns, transferred to galvanised tin and began cutting folding soldering. After painting and a bit of distressing the paint they look pretty good if I say so myself. Ben in Toronto

The following photos have been uploaded to the For Sale album of the T1154-R1155@groups.io group. DSCF2963.JPG DSCF2964.JPG DSCF2965.JPG DSCF2966.JPG By: militaryoperator

Subject: New member Hi all I sent a previous introduction ( declined ) mail with my spell check on, now off wanted to say that I have a working as issued R1155 that gets turned on now and then. I was working on a faulty power cable for the D/F and somehow our dog got a hold of it thinking it was a chew toy and destroyed it. I was on the net looking for two replacement female jones plugs, is when this group was noticed and I joined that same day. I tend not to join in but I do lurk and see what is discussed as well as on WS19 groups. So that is my story, wanted to say hello to all on this site. Ben in Toronto