Title: T-368 experienced operator? Post by: KA3JIJ on November 19, 2022, 04:27:01 PM I've looked thru the Military Amateur Radio section amd found nothing, so wanted to reach out to the community. I have a T368 inherited form an SK. He was on the air with this radio and an R390A 2.5 years ago. He supplied me with all the manuals, so I'm reading up on operations. I'm hoping I can find someone familiar with these radios that can give me a quick "hands on" walk through of getting it back on the air. It appears to be in great shape, but I did note that the prior owner had a modulation scope and frequency counter associated with the unit, so not sure if there were any problems he was trying to chase, or if these tests were merely good practice.
I look forward to any knowledgeable users getting back to me so I can get this classic back on the air. KA3JIJ Title: Re: T-368 experienced operator? Post by: Opcom on November 21, 2022, 02:08:33 AM OK well there -could- be some issue with it, but a mod scope and counter are accepted good practice for using classic non-digital stuff today, so they should not raise the spectre of impending doom or imperial entanglements.
Title: Re: T-368 experienced operator? Post by: KA3EKH on November 21, 2022, 08:59:05 AM Think the things to remember about using that transmitter are:
First- have a good AC circuit. Being its 120 volts, it’s going to suck down a bunch of current when transmitting, so no cheap plug strips or extension cords! Radio work best with dedicated circuit. Second- learn how to tune and load the radio into a dummy load and power meter first. In military service you always had a ME-165 wattmeter dummy load and you would tune into that first and then switch to the antenna. Third- don’t defeat the interlocks! The interlocks become interment on some transmitters so some Hams bypass them. The transmitter has over two thousand volts on the plate that can easily kill you. The interlocks are there to keep the HV off when the drawers are pulled out. Forth- This one is one of my favorites, do not ever pull out more then one drawer at a time. If you pull two drawers out at the same time the transmitter may fall on you and that’s bad news. In military service the transmitter has outriggers that extend out the front and back of the radio and many Hams remove them so they won’t stub their feet. Also saw a couple where they not only removed the outriggers but they also installed wheels or coasters directly under the transmitter and this is incredibly stupid because it makes it more unstable. Modifications- somehow there are a ton of modifications out there. Hacking the speech input amplifier by bypassing the bandwidth and limiting stuff and the like. Its up to you because you own the radio but I will tell you the stock audio from a T-368 is good and never liked the idea of hacking the speech amplifier, works good with a military carbon microphone but somehow most Hams think you have to run a D-104 that don’t work as well. There are several modifications out there for the output tank with one that includes isolating a lot of the tank from the HV or relocating where the plate current meter is installed and once again that’s all up to you. But if you have the stock plate current meter remember that its in the high side of the HV supply. On the old transmitters they did not have that much insulation around the meter and that could be an issue. Title: Re: T-368 experienced operator? Post by: Tom W2ILA on December 17, 2022, 06:16:01 PM Turn the filament voltage pot counter clockwise before powering up just in case someone decided to twiddle the dial. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
Do you have the book with the tuning curves? Preset the tune and load before keying. Tune up with the power supply switch on low power. If you try to tune on high power and the tank is far off resonance, the overload will trip. |