813 anode choke - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

G3PIJpeter · 16th Jul 2017, 2:37 pm

While I am sure that no owner of an LG300 will want to make these changes, I have included these photos to show that a previously-wrecked example can be adapted for DDS drive on 160 and 60 metres.
The original anode choke has sufficient inductance to work on 160 but I replaced the rather grotty pi-tank switch with an 8-section NOS Heathkit ceramic item with sections in parallel to short out the pi coil and also to switch in extra tune and load capacitance for Top Band.
In either CW or AM mode (and with the help of a variac on the EHT supply), the transmitter will deliver the maximum permitted up to 150 watts of carrier in the appropriate allocations on both bands.
73
Peter

16th Jul 2017, 2:37 pm	#21
G3PIJpeter Hexode Join Date: Nov 2011 Location: Chippenham, Wiltshire, UK. Posts: 323	Re: 813 anode choke While I am sure that no owner of an LG300 will want to make these changes, I have included these photos to show that a previously-wrecked example can be adapted for DDS drive on 160 and 60 metres. The original anode choke has sufficient inductance to work on 160 but I replaced the rather grotty pi-tank switch with an 8-section NOS Heathkit ceramic item with sections in parallel to short out the pi coil and also to switch in extra tune and load capacitance for Top Band. In either CW or AM mode (and with the help of a variac on the EHT supply), the transmitter will deliver the maximum permitted up to 150 watts of carrier in the appropriate allocations on both bands. 73 Peter Attached Thumbnails Last edited by G3PIJpeter; 16th Jul 2017 at 2:43 pm.