Tram D201 BA circuit board upgraded replacement suicide resistant

Description: This is an upgraded replacement for the infamous "BA" plug-in circuit board found in Tram D201 radios built with large printed-circuit boards. This does *NOT* fit the original "open chassis" or "hand-wire" version of the Tram D201. No place to plug it in on that model, no need to. This circuit board stands up alongside the large 6L6GC audio-power tube in the circuit-board D201 and D201A models. I am going to put this **DISCLAIMER** up front in this listing. The D201 models are subject to a long litany of reliability issues. A lot of things can go bad in 40-plus years. Replacing the radio's original BA board will *NOT* fix trouble caused by: A bad relay, a bad speaker, bad tube sockets, bad tubes, failed solder connections, noisy rotary switches/controls or any other part of the radio outside of this printed-circuit board. This is *NOT* a totally-stock copy of the factory design. It has been enhanced and beefed up to run at lower temperatures. There is a tiny wire jumper on the upper-left corner that will reduce the bass response of the radio's audio. Anyone who sounds too "boomy" may want to use this. And if you don't find that an improvement, simply stitch a wire back in its place. Tram supplied a one-tenth (1/10) Amp fuse on their BA board. We recommend either a one-eighth ( 1/8) Amp or at the VERY largest rating a 150 mA. fuse. Those are kinda rare.The upgraded BA-plus board comes with a spare 1/8-Amp fuse that protects the audio tube and with new header pins, but more on those later. The factory-original circuit board is famous for making "CRACKLE, POP!" sounds when touched. There is more than just one simple cause behind this single symptom. This board solves some of those causes. More on that later. The original BA board had overheating problems. We have improved this by boosting the power rating of all the parts that get hot by a factor of 2 to 1 or more. The heat energy this board must unload is not reduced, but larger parts with more surface area will have a lower temperature rise. Same heat energy, lower operating temperature. The factory-original BA board used a dirt-simple one-transistor 14-Volt regulator circuit that did not have any surge protection. This board uses a LM7815-type regulator that shuts down if it overheats or gets overloaded. It also has a larger heat sink. This permits the use of 12-Volt accessory gadgets, (like a digital frequency display?) without the overload problems the stock BA board would have. The very-last production runs of the 40-channel D201A radio used a version of the BA board that had jumper wires in place of the 220-ohm cathode resistors used in the 23-channel and earlier 40-channel production. This board will replace that one, with only a minor modification. About those "CRACKLE, POP!" problems. Cracked solder connections to the pins where this board plugs in are the most-common cause. Resoldering will fix that, unless one of the foil traces attached to those pins is cracked. The solder connections to the sockets on the BA board itself sometimes come loose, but ours won't. Dirt, tobacco-smoke tar or oxidation can make the socket connection noisy. A good scrub with rubbing alcohol or other solvent fixes that. The last and most-aggravating cause is a worn-out surface on the round pins themselves. The spring contact in the BA board's sockets presses against the surface of those round pins in a way that concentrates all the force into a tiny surface area where they touch. Pull out the BA board enough times and the plated layer on the pin's surface wears away. That electroplated layer is what keeps the connection quiet. Once it wears away, the board will always be noisy when you touch it. We include new, shiny 6-pin headers with square pins. The force against the surface of a square pin is spread over a larger area. Takes much, much more abuse to wear them out than the original round pins. R604 is a 82-ohm 1_Watt resistor connected to pin 8 of the 6L6 audio-tube socket. The 15-ohm resistor seen in one picture is to replace that one. Here's the arithmetic: Old two resistors were 220 ohms each, plus that 82 ohms all in series. This adds up to a total of 522 ohms. Plus or minus ten percent, typically. The same resistors on our board are 250 ohms each. To achieve the same total we add the 15-ohm resistor in place of the original R604. Yeah, that's 515 ohms, not 522. Ahh, seven ohms' difference? That would be a difference of just over 1 percent. Not enough to be a problem. And if your R604 looks okay, just leave it in place. Feel free to simply plug the new BA+ board in place of the old one. If the original round pins are not worn out, you're done. It ain't broke no more. But if the "crackle" issue persists be warned. The new square pins are a tight fit in the round circuit-board holes. If you are confident of your mechanical skills, replacing the pins would be the thing to do. And if you think you may damage the circuit-board foils trying to cram larger pins into smaller holes, you should hire someone with the skills to do this without damage to the audio circuit board. Once more: This is an upgrade. A modification. If you wish to restore a radio to stock original condition you can still obtain a copy of the original BA board. Goldeneagleradios sells a proper copy of the factory BA board, but the build quality is *FAR* better than the Tram factory board. If an authentic restoration is your objective, please do not hesitate to buy the stock board from them. I vouch for them 100 percent. Just can't include a direct web domain in this listing. Not allowed. There are NO RETURNS AT ALL FOR ANY REASON OF ANY KIND!No matter how good they sound. We ship no later than the second business day following receipt of cleared payment. I prefer USPS. It's been VERY reliable and comes with tracking. I will insure it for the final sale price. IF YOU PREFER A DIFFERENT **USA ONLY** SHIPPING METHOD, CONTACT ME **BEFORE** YOU PAY! I will prepare a quote for the method you specify and send you an invoice for the corrected amount. This option is available to USA destinations ONLY! !!!! NOTE !!!!Shipping to destinations outside the US are by the Ebay GSP or Global Shipping Program. How much that will cost you is anybody's guess. Ask Ebay if you want to know. Maybe they'll tell you. They won't tell me. Maybe they should rename the "GSP" the "Global Secret Program". GSP ONLY!! GSP ONLY!! GSP ONLY!! No, I will NOT ship direct if you are outside the USA and its colonies. GSP ONLY!! GSP ONLY!! GSP ONLY!! If you know what it is and what it's for, you can decide if you want or need it. And if you don't know what it is, you probably don't need it. Trust me on this. All routine Ebay precautions apply. Scammers take your nonsense elsewhere. Please. Thanks for looking!

Price: 85 USD

Location: Louisville, Kentucky

End Time: 2024-12-18T04:11:33.000Z

Shipping Cost: 0 USD