Post by 9fb177 on Aug 6, 2019 20:22:18 GMT -5
I finally have my Tram D201 stable and working well on the air. I've had a number of QSOs and the reports I'm getting are great!
In addition to recapping, replacing power resistors, shoring up connections, removing bad mods, new BA board ordered from Barkett, replacing a few tubes, troubleshooting of problems, etc, I did a number of things that I think improve the radio, and thought I'd share them!
1) Heat! Wow! This Tram D201 has much less heat damage to the receiver board than another one I own. In fact, the only traces damaged on this one surround the resistors R418 and R419, the plate resistors of the meter circuit. I started with the idea of buying big bad resistors and replacing them raised up from the board, but I suspect that no matter how large these resistors are, they have a lot of heat to dissipate, and some of it will flow down the leads and into the board. I purchased a couple of 30W 47K resistors in to-220 packages, bolted them to a heatsink and mounted the heatsink in the corner of the radio. I thought this solution would help protect the circuit traces from heat.
2) Heat! I wanted to impove the airflow through the radio. Not sure if this is a good idea, and I'd like to hear other ideas if you have thoughts, but I raised the feet of the D201 Using washers with longer bolts, to increase the clearance, and then I slipped a 3 fan laptop fan underneath. It seems to really help. This photo shows how the laptop pad fits nicely under the tram.
3) I'd like to use this radio on the air from time to time just for the joy of running vintage. I added a hard key jack to key my Pride DX-300, and also added an external VFO jack with a switch to allow me to use the internal or external VFO. The Tram VFO is kewl, but it's not very stable considering how picky everyone is about frequency accuracy in 2019. I retrofited an old Pal VFO case with a DDS VFO, and it works extremely well. I used a DDS VFO that is sold as an add-on for vintage amateur radios, and it was rather pricey. If you know of cheaper DDS units I could have used, I'd like to hear about it for other projects.
Here's a photo of the finished radio. I'm enjoying using it, and I'm pleased as punch! Thanks for listening!
73,
Kevin - 177
In addition to recapping, replacing power resistors, shoring up connections, removing bad mods, new BA board ordered from Barkett, replacing a few tubes, troubleshooting of problems, etc, I did a number of things that I think improve the radio, and thought I'd share them!
1) Heat! Wow! This Tram D201 has much less heat damage to the receiver board than another one I own. In fact, the only traces damaged on this one surround the resistors R418 and R419, the plate resistors of the meter circuit. I started with the idea of buying big bad resistors and replacing them raised up from the board, but I suspect that no matter how large these resistors are, they have a lot of heat to dissipate, and some of it will flow down the leads and into the board. I purchased a couple of 30W 47K resistors in to-220 packages, bolted them to a heatsink and mounted the heatsink in the corner of the radio. I thought this solution would help protect the circuit traces from heat.
2) Heat! I wanted to impove the airflow through the radio. Not sure if this is a good idea, and I'd like to hear other ideas if you have thoughts, but I raised the feet of the D201 Using washers with longer bolts, to increase the clearance, and then I slipped a 3 fan laptop fan underneath. It seems to really help. This photo shows how the laptop pad fits nicely under the tram.
3) I'd like to use this radio on the air from time to time just for the joy of running vintage. I added a hard key jack to key my Pride DX-300, and also added an external VFO jack with a switch to allow me to use the internal or external VFO. The Tram VFO is kewl, but it's not very stable considering how picky everyone is about frequency accuracy in 2019. I retrofited an old Pal VFO case with a DDS VFO, and it works extremely well. I used a DDS VFO that is sold as an add-on for vintage amateur radios, and it was rather pricey. If you know of cheaper DDS units I could have used, I'd like to hear about it for other projects.
Here's a photo of the finished radio. I'm enjoying using it, and I'm pleased as punch! Thanks for listening!
73,
Kevin - 177