Jim Heath W6LG shows how he tunes a linear amplifier for maximum output power in watts. He gest about 1200 watts from a Drake L4b Linear Amplifier from the 1970's.
Gosh Jim, I did this same thing on USS Carl Vinson CVN 70. Replaced all that z700 tubes. Had NIViking tuners. Stole "2" 35 ft horizontally polarized winps off the stern of the aircraft carrier... Put out1500 watts pep. And touched the Earth with RF!!! I'm not a radio man I'm just a ham BM1.... Knuckle dragger....
Excellent! Doing it that way for many years. I have a Drake L7. Got it used in about 1990 and still using the same tubes after 22 years! I do keep the output under 1000 watts most of the time, but it gets a lot of contest use.
Hello Jim. Geat to see and hear you again. Awesome video as always. I picked up a couple of Kenrich Eagle 10 meter amps that used sweep tubes. I'm putting two GI-7B Russian tubes in one and GI-46B in the other and installing an ATU instead if a band switch in them. Fun projects. I just ordered a pair of 813 tubes and will be my next project. All the best sir. Still in my prayers. 73
Have had an 811H amp. for a year now. After about 5 hours of use I had one tube fail sent it back to Ameritron they said the tube had lost it's vacuum in the base. Sent me a new one and so far all doing fine. It came with the grid current protection circuit so I can only load it up to 50 watts and no more but I do get 800 watts PeP out with it and so far am very happy that I have a good signal without spending $5K or more.
I just rebuilt a Gonset 101 with four 811A's. I greatly appreciate this video for showing me how to tune it up. It works great. I have both a Tiny SA Spectrum Analyzer and a Nano VNA and it is showing a very clean output.
Jim, I really appreciate this video, especially now when I've got a line on a 4b. The seller bought an estate and this was part of it. He's asking about $1200 and states it was working before the operator went SK. Given, the triodes may be dead or tired, However, my question-most likely too big to answer-is what or where should I look to assure that the amp has still some value. As usual, your videos are a joy and so informative. 73 OM. AA7MO, Mike
New tubes could be around $700. A cracked bandswitch is fatal. I would not pay more than $500 to $600. The other option would be to test it first. You give them a deposit of a few hundred. There is so much that could be wrong. A broken meter....almost impossible to find. The darn on and off switches are very expensive. Mike, offer very low or be allowed to test it first. 73, Jim
Hi Jim...at 9:37 'I would increase the Load control just a tad'...except at that moment, your hand was adjusting the PLATE not the LOAD. Did you still mean increase the Load ? I do always enjoy your videos. Take care and God Bless. Thank you. Rom. 1:20.
I thought you were suppose to tune with a pulsed carrier ?? I think it’s supposed to lower the duty cycle and be easier on the tubes ?? I feel teaching solid carrier could be detrimental to sum tubes that are made of inubtaninium
