Uncle left me his old HF rig, is it worth selling or scrapping?

A working TS-570 usually brings somewhere between $250 and $450 depending on condition and which version you have. They were well built, solid little HF rigs and there's steady demand from newer hams looking for an affordable first radio. Not retirement money, but definatly better than whatever someone tosses at you from a folding table at a hamfest. The wide range in online listings is mostly sellers guessing high, so ignore the extremes and look at what acutally sold rather than what people are asking.

You can test the receive side without any license or transmit gear. Snip a random length of wire, strip one end, and clip or tape it into the center pin of the antenna connector. Tune to 10 MHz and you should hear WWV, the time signal station, plain as day if the receiver is healthy. Then spin across the shortwave broadcast bands, you'll get all kinds of stations. If audio is clean everywhere, odds are the transmit side is fine too, it's uncommon for one to die while the other keeps working. The usual problems on these are a leaky memory battery on the circuit board and dirty controls, so listen for scratchy noise when you turn the volume or tuning knobs. The sticky button is almost certainly just grime, a shot of contact cleaner and some repeated pressing normally sorts it.

When you sell it, be upfront that transmit is untested. Buyers in the hobby are used to that phrasing and it won't scare anyone off, expecially since it powers up and receives. Honestly, most buyers will test it themselves with their own equipment.

Best market is the local radio club classifieds or a club mailing list rather than general auction sites. You avoid shipping a heavy radio full of glass and circuit boards, and the buyer pool there actually knows the model. A hamfest table is fine too, just price it near the middle of that range and be willing to haggle a little. Keep the manual and the original microphone with the radio. Having the complete package nudges the price up and the buyer will appreciate it.

Yeah, keeping the manual and the original mic definitely adds value, that is solid advice. I went through the same thing a couple of years ago with a diferent rig and noticed a clear jump in price just because the full kit was present. When people are looking at that older equipment, having the documentation makes it feel complete and professional rather than just a pile of electronics.

It's way better to go through a local club and avoid shipping somthing that heavy. I learned the hard way that parcel shipping a radio full of glass and heavy chassis ends up being a real headache and can even dent the unit in transit.

I think you might be underestimating the likelihood of major component failure across the board. You claim it is uncommon for the transmit side to die while the recieve side is still healthy, but my own experiance with older tube gear shows that internal power supply issues often kill both systems at once. It isnt always a simple capacitor failure on the memory circuit. It's ussually more systemic when the unit is that age. If the power board starts failing, it will usually take out several related components. You really need to factor that into the price you list, because if the whole power plant is shot, the unit is just a collection of parts, not a working radio. Are you sure you haven't seen specific failure reports on these units?

Update: I dug the rig out again and tuned around on receive with a bit of wire stuck in the antenna socket, and it picks up stations clearly, so the receiver side seems fine. One reply mentioned the price depends on which version it is, and honestly I can't tell from looking. Is there a marking on the back panel or somewhere in the manual that shows the difference?