Hey guys i was just digging around in my grand fathers storage, an came cross his old radio stuff i have a palomar 300a without a powersupply was wondering if anyone could direct me in the right way to get a powersupply for it since its a 2-peice unit. any help is appreicated thanks!
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ISO palomar 300a powersupply
- Thread starter 1West8side7
- Start date
There is more than one.
Somewhere here there is a good thread about how to identify the amp you have.
73
Jeff
Somewhere here there is a good thread about how to identify the amp you have.
73
Jeff
do you know where i would beable to buy one online ? or will i have to buy from someone who has it?
do you happen to know the site or where he was able to find them i cant seem to find that infomation on the post, also do you know anyone with them for sale
Unfortunately over the years many Palomar 300a amplifiers have been separated from their power supplies. When the amplifier falls into someone's hands who's unfamiliar with it, they often don't know this is a two-piece unit unless they've seen it connected. In that case the power supply usually gets discarded later.
If you find the right version to fit your unit, you could expect to pay $100 or more for a used one. Since each of the six tubes also costs nearly as much, you'll want to have them tested before proceeding. If the tubes are not good, there is no point in wasting the money to retube it and buy the transformer.
If you find the right version to fit your unit, you could expect to pay $100 or more for a used one. Since each of the six tubes also costs nearly as much, you'll want to have them tested before proceeding. If the tubes are not good, there is no point in wasting the money to retube it and buy the transformer.
so basically your saying since i dont have the 2-peice transmitter, im pretty much out of luck ha, i know theirs 2 types of transmitter just trying to get this thing working, i dont mind paying money for the the transmitter i jus want to get this thing working
No one is going to stock new replacement transformers, you have to figure out what power supply you need and look for a used one or a replacement that will work.
Chris, Nomad might be able to point you in the right direction, but it's not a part you can just call and order.
73
Jeff
Chris, Nomad might be able to point you in the right direction, but it's not a part you can just call and order.
73
Jeff
i figured that, i hope i can find someone with some spares that are in working order.
That transformer tyically had no markings on it. Some of them had the Palomar logo, the stylized letter "P", but that's all.
Most of them would get separated from the amplifier. Someone picks it up, has no idea what it's for, and it goes to the dump. The amplifier actually looks like something that might have a purpose, or at least some value. Probably why they don't get ditched as often, and turn up orphaned with no transformer.
73
Most of them would get separated from the amplifier. Someone picks it up, has no idea what it's for, and it goes to the dump. The amplifier actually looks like something that might have a purpose, or at least some value. Probably why they don't get ditched as often, and turn up orphaned with no transformer.
73
You'll at least need to know if you have a good set of tubes in that amplifier before proceeding. You can already assume the amplifier will need all new electrolytic capacitors and a transformer that won't be less than $100. If you also need nearly $600 worth of tubes replaced, this would absolutely not be economical to repair.
Even without access to a tube tester, there are some things you can check for. For example are any of the internal cathode fuse links burned open? This tiny fusible link goes from pin 2 on the bottom of the tube to the center cathode element. The fusible link is right underneath the cathode. If burned open, that tube is completely dead.
The other thing you can look for is the coloring on the clear portions of the glass envelope. If they appear to be tinted or are darker than clear glass, this is an indication the tube has been subjected to heavy use. Also look at the edges of the silver colored, getter flash marks on the envelope. If the edges have turned white or you can see where the silver spot has gotten smaller (visible by a larger stained outline), this is also a sign of heavy use.
Even without access to a tube tester, there are some things you can check for. For example are any of the internal cathode fuse links burned open? This tiny fusible link goes from pin 2 on the bottom of the tube to the center cathode element. The fusible link is right underneath the cathode. If burned open, that tube is completely dead.
The other thing you can look for is the coloring on the clear portions of the glass envelope. If they appear to be tinted or are darker than clear glass, this is an indication the tube has been subjected to heavy use. Also look at the edges of the silver colored, getter flash marks on the envelope. If the edges have turned white or you can see where the silver spot has gotten smaller (visible by a larger stained outline), this is also a sign of heavy use.
I'll also mention that the pins on the connector that attaches to this power transformer, are prone to oxidation. Especially if the connector has not been plugged into the amplifier for a long time.
This has the potential to cause problems with heating on both the high current primary and filament pins. It's a good idea to clean them with a soft wire brush if you see any signs of oxidation. If this is ignored, it can overheat the connector and damage the mating plug on the back of the amplifier.
To clean the connector on the back of the amplifier, use contact cleaner and plug the plug in and out at least 10 times. Do this after you've cleaned the connector on the power supply.
This has the potential to cause problems with heating on both the high current primary and filament pins. It's a good idea to clean them with a soft wire brush if you see any signs of oxidation. If this is ignored, it can overheat the connector and damage the mating plug on the back of the amplifier.
To clean the connector on the back of the amplifier, use contact cleaner and plug the plug in and out at least 10 times. Do this after you've cleaned the connector on the power supply.
There is a thread in Copper Electronics that goes into detail about the two identical transformers for the Palomar 300A ...... one is a 300 volt and the other is a 600 volt .... I own three 300a,s two black face with 6KD6 tubes and 1 white face with 6LF6 tubes, all three operate with the 300 volt transformer ! The short is ..... They both look alike and have the same plug ....... The rectifier used inside the amplifier for the HV winding has to match it ! The version that had the rectifiers arranged as a voltage doubler calls for the 300 volt transformer .... the version that has the "Bridge" rectifier calls for the 600 volt transformer ! You can guess what will happen if you plug the 600v transformer into the amp that calls for the 300v transformer ! The thread at Copper Electronics explains how to test just the transformer to find out whether it is the 300v or the 600v ...... hope this can help !
No sweat. The parts to build the 'clone' transformer are here and still waiting for one of those "round tuits". Found them the other day, looking for something else. The steel box I bought has flanges around the opening that need to be trimmed so the big transformer can be crammed into it. The smaller one for 12 Volts will fit fine.
Thought it would be a slow-season summer project. Still waiting for a slow summer.
73
Thought it would be a slow-season summer project. Still waiting for a slow summer.
73