Good morning. My name is Jeff and a new member to this forum. A short background; I used to work as a Cable Television Technician back in the late 90’s and early 2000’s. I dealt with problems from the modulators through miles of lines and amplifiers to other devises and to the T.V. sets, using frequencies up to about 400 megahertz. I have built a few crystal radios before, but stopped about five years ago. However, I just might build a few this winter.
Two months ago I bought an old Admiral radio from 1947. I got it working in satisfactory condition and figured I better build a house transmitter for it. So I built the Lil 7 transmitter from “Phil’s old radios” website. The transmitter was very unsatisfactory. Probably my fault. While scouring the internet for solutions to make this transmitter work better, I found that most folks find this transmitter design unsatisfactory. While I have found a few ideas on how to make this work better, with my frustration level rising past 90%, I have decided to try a new design all together. I have studied this website for about a month on several issues, a transmitter being one of them, and found the 6888 transmitter to be very well liked. Unfortunately most of the discussions and drawings are over a decade old and the drawings of the schematics are not available.
My question is: Where can I find a schematic and part list of the 6888 style transmitter? If there is more than one version, which one would fit my preferences? My preferences are a transmitter that will transmit 25 feet from a headphone jack of a stereo to 5 tube radios like my Admiral and if possible a crystal radio. Secondary preference would be to transmit from a smaller device like a MP3 player or a Walkman. The Admiral only picks up one station at 570 in the morning; in the evening most the entire AM band is full of weak to strong signals. So I will be satisfied with day time transmitting only.

Thank you for reading this,
Jeff

Welcome, don't be a stranger... I modified links to be "clickable" in the "Three Different 6888/6GY6 Transmitter" thread yesterday... Most all the info you need is there...

Note these transmitters are fairly robust(at least if properly tuned)... There have been issues where the RF overloads front end of nearby radios...

For a transmitter with a bit less output, look at the LM386 version, schematic is "up" in that thread...

viewtopic.php?f=12&t=193042

Tom

Thank you. That's the schematics I have been trying to find. I will study them and figure the one i want.

I think I will start out with the first or original design. Looks within my skill level. A question for you though, or anyone who has the answer; is component placement important? Such as near the crystal?

Jeff