Recently acquired a killer D 104 with an original Tweety Bird installed from another forum member here. Enjoying the heck out of it. Came with a used battery installed and after a week or so the battery killed off. This will be my main mic now and it sees daily use so I'm going to be going through the batteries. Also, the tweety installed is very fast firing on continuous repeat. I noticed the repeat speed started slowing a little bit over the last few days before the battery go too low and it sounded better that way. With a new 9V installed it is super fast.
I could go into the tweety and replace one of the capacitors to slow it down but the things are delicate and I'd just as soon not tinker with it if I don't have to.
So I considered that I could "feed" the mic with a continuous and custom lower voltage, below that of a new 9V battery, by modifying it with a battery eliminator setup via an adjustable power supply. I didn't have a small one for this use so I was going to look around on ebay for one. I had mentioned the situation on our local channel and one of the guys piped up and said he had one that he wasn't using. It is a real nice BK Precision triple output fully variable bench testing supply. It's only does .5 amp on the two high voltage outputs. It is too small to even run a 4 watt radio and so the guy had no real use for it. He had picked it up cheap somewhere and agreed to sell it to me for what he paid which was only $20 !! It works 100% as should and the meter is dead on accurate as well.
I wanted a quick-connect arrangement so I installed an 1/8" female phono jack in the base of the mic and a matching male plug on the wire going to the supply. Simply paralleled the power hookup inside the mic. On first use the mic keyed as soon as I supplied power to it. Dangit boy couldn't figure out what was wrong and had me frustrated for about a half and hour. The hookup was really simple and it seemed that it should have worked as-was.
Finally figured out that the mic, or this particular one anyway, uses battery negative as part of the keying circuit. The phono jack I installed has the all-metal body around the larger outside piece. So as normally installed, the body of the jack was grounded to the mic base. I took it back out and insulated the jack body so that is doesn't come into metal against metal contact with the mic base and that solved the problem.
Using the 2nd variable output for the 12V fans blowing on the amp. All working out great
So take this factor into consideration if you ever decide to rig yourself up an external voltage source for a desk power mic to eliminate the battery.
I could go into the tweety and replace one of the capacitors to slow it down but the things are delicate and I'd just as soon not tinker with it if I don't have to.
So I considered that I could "feed" the mic with a continuous and custom lower voltage, below that of a new 9V battery, by modifying it with a battery eliminator setup via an adjustable power supply. I didn't have a small one for this use so I was going to look around on ebay for one. I had mentioned the situation on our local channel and one of the guys piped up and said he had one that he wasn't using. It is a real nice BK Precision triple output fully variable bench testing supply. It's only does .5 amp on the two high voltage outputs. It is too small to even run a 4 watt radio and so the guy had no real use for it. He had picked it up cheap somewhere and agreed to sell it to me for what he paid which was only $20 !! It works 100% as should and the meter is dead on accurate as well.
I wanted a quick-connect arrangement so I installed an 1/8" female phono jack in the base of the mic and a matching male plug on the wire going to the supply. Simply paralleled the power hookup inside the mic. On first use the mic keyed as soon as I supplied power to it. Dangit boy couldn't figure out what was wrong and had me frustrated for about a half and hour. The hookup was really simple and it seemed that it should have worked as-was.
Finally figured out that the mic, or this particular one anyway, uses battery negative as part of the keying circuit. The phono jack I installed has the all-metal body around the larger outside piece. So as normally installed, the body of the jack was grounded to the mic base. I took it back out and insulated the jack body so that is doesn't come into metal against metal contact with the mic base and that solved the problem.
Using the 2nd variable output for the 12V fans blowing on the amp. All working out great
So take this factor into consideration if you ever decide to rig yourself up an external voltage source for a desk power mic to eliminate the battery.
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