You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
When the 40 channel radios came out in 1977 the P500 manual set the new length at 22' 6' to cover the higher frequencies allowed. Here is a copy of the 1981 manual.
They just need to be assembled like the original P500 to work properly on 11 meters, which is what you did there. Without an electrical connection through the matching rod from the coax to the antenna mast, there is no way it could work. Poor assembly on the part of the manufacturer, for sure.
Actually, the TRC449, 457,and 458 were only made in 1977 and 78. In 1979 the PD858 board was discontinued and the MB8719/MB8734 board was introduced. The TRC450 and 490 replaced the 449 and 458. There was no replacement for the 457.
The schematic shows resistors 301-314 as 680 ohms. According to the manual parts list they are individual ones and not a couple of resistor networks. You may want to check these. If they are bad or too high in value the segments won't light.
Also, a sniffer probe is a good thing to have. It can be used to read a signal without direct contact. A direct connection can sometimes pull the signal down a bit and give you an incorrect frequency reading. If the sniffer probe it is insulated, you won't have to worry about touching something...
The Tram Titans like a few other DSBSC radios transmitted on both sidebands at the same time, so their output was divided between the two. Wasn't much better than AM.
That's a later model, as it has fixed bias for the audio tube. The yellow cap, blue thumb wheel, electrolytic cap and a few resistors on the audio board are the giveaway. The D201A doesn't use the "B" side of those two tubes to control the meter like the 23 channel radios did. It uses a UA741TC...
I'm a little late to the party, but I had the same problem with one of those I worked on. The crystal was off-frequency when I measured it and had to replace it. Was all good after that.
Sounds like the LSB crystal is out of tolerance and the trimmer can't bring it onto the correct frequency. I've seen that quite a few times in those 858 PLL radios. They are 45 or 46 years old now.
The leg is missing because it's not needed. The leg and the metal tab of the transistor are connected, so there is no need for the leg. This is used as the regulator for the 14 vdc circuits. If you measure about 14.2 vdc on the output of that part which is the emitter, it is okay. The emitter is...
Here is a diagram from the circuit board D201manual. The board is the same as the vox radio's board, except the vox board used round sockets and pins and the later D201 and D201A used square ones. The diagram clearly shows the orientation of the caps.
Do you have a manual or schematic for it? If not, you can download them here: https://web.archive.org/web/20210302170832/http://cbtricks.com/radios/tram/d201a/index.htm. There are board diagrams in the manual that will help you identify the parts. Looks as though most of the resistors that...
I've done that many times over the years for people. They just have to realize they won't have channel 39. Only 36,37,38,and 40 unless they want to somehow add the extra 4 MHz crystal that the 40 channel radio has.
Here's a NY Times article from 4/28/1983, the day the FCC ended CB licensing. https://www.nytimes.com/1983/04/28/us/fading-cb-craze-signals-end-to-licensing.html
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.