KC9LQV
Member
Hey all, sorry for the delay, but in the "Harris AL-1500 locomotoive radio" thread, I mentioned restoring some old Motorola railroad radios for a railroad museum and there seemed to be some interest. So I wanted to post those pics of the Motorola "simulations", along with pics of the new/rebuilt radios as they're installed in the tower.
The first pic shows the gutted Mocom 70 (which was the L&N/SBD/CSX radio) chassis with the Bearcat BC700A mounted to the frame. It faces backward so the squelch and volume knobs can be accessed through the rear panel if needed. I had originally set it to run on a 9v battery, but ended up switching it to a wall wart.
Here's a closeup of the back side of the panel, showing the wiring into the speaker and volume pot. The volume on the scanner is just set to about 3/4 full, and that output goes through the volume pot so it can be adjusted via the front panel. The nice thing about the BC700 is, being a mobile unit, it has a LOT of volume output, and when running through the nice big Moto speaker, there's enough volume to hear the radio clearly even while trains are running through the interlocking. The "black box" is a simple circuit designed to simulate the proper operation of the RX/TX lamps on the front panel.
I replaced the original lamps with LEDs, and wired the mic into the switch so when you "key the mic" the TX LED comes on. The power for the LEDs is switched through the on/off volume pot, so when you turn the radio off, the volume is cut out and the LED goes out, just like the real deal. Like so:
Here's how the operator's desk looked in 1989:
And here's how it looks now. Virtually everything on the desk is a replacement for the original equipment, even the ringer bells and the swing arm lamp. As you can see, we've still got a few things we need, but we're getting close.
Now for the Conrail radios: I essentially did the same thing with the T1602, except that the scanner is hidden under the shelf in the cabinet out of sight. The power wire to the wall wart and the speaker wire run through an empty strip of coax casing, so they don't stick out like a sore thumb. The RX/TX lights work in exactly the same way as the Mocom, and the whole thing is wired through the On/Off and volume pots on the top panel.
Here are the original radios in 1989:
And the replacements in 2010:
Note I even had a laser-etched asset tag for the T1602 with the correct serial number made. (Yeah, I'm OCD like that <g>)
The radio on the left is a GE Custom MVP that's fully intact. All I have to do is get crystals made, and it *should* be operational.
Anyway, I hope this is all of interest. I've had a lot of fun restoring these radios and "faking" their original operation. Most visitors to the museum don't even realize they're not the actual radios. Which is pretty gratifying.
Shameless plug - Our web site: The Haley Tower Historical & Technical Society
The first pic shows the gutted Mocom 70 (which was the L&N/SBD/CSX radio) chassis with the Bearcat BC700A mounted to the frame. It faces backward so the squelch and volume knobs can be accessed through the rear panel if needed. I had originally set it to run on a 9v battery, but ended up switching it to a wall wart.
Here's a closeup of the back side of the panel, showing the wiring into the speaker and volume pot. The volume on the scanner is just set to about 3/4 full, and that output goes through the volume pot so it can be adjusted via the front panel. The nice thing about the BC700 is, being a mobile unit, it has a LOT of volume output, and when running through the nice big Moto speaker, there's enough volume to hear the radio clearly even while trains are running through the interlocking. The "black box" is a simple circuit designed to simulate the proper operation of the RX/TX lamps on the front panel.
I replaced the original lamps with LEDs, and wired the mic into the switch so when you "key the mic" the TX LED comes on. The power for the LEDs is switched through the on/off volume pot, so when you turn the radio off, the volume is cut out and the LED goes out, just like the real deal. Like so:
Here's how the operator's desk looked in 1989:
And here's how it looks now. Virtually everything on the desk is a replacement for the original equipment, even the ringer bells and the swing arm lamp. As you can see, we've still got a few things we need, but we're getting close.
Now for the Conrail radios: I essentially did the same thing with the T1602, except that the scanner is hidden under the shelf in the cabinet out of sight. The power wire to the wall wart and the speaker wire run through an empty strip of coax casing, so they don't stick out like a sore thumb. The RX/TX lights work in exactly the same way as the Mocom, and the whole thing is wired through the On/Off and volume pots on the top panel.
Here are the original radios in 1989:
And the replacements in 2010:
Note I even had a laser-etched asset tag for the T1602 with the correct serial number made. (Yeah, I'm OCD like that <g>)
The radio on the left is a GE Custom MVP that's fully intact. All I have to do is get crystals made, and it *should* be operational.
Anyway, I hope this is all of interest. I've had a lot of fun restoring these radios and "faking" their original operation. Most visitors to the museum don't even realize they're not the actual radios. Which is pretty gratifying.
Shameless plug - Our web site: The Haley Tower Historical & Technical Society
