Roberts R861 worldband receiver repair part 1: Initial look and fault finding process
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- Опубліковано 1 жов 2024
- Paypal link below.
FOR SALE www.radiocrunc.... In for repair is a lovely Roberts worldband radio. This is a rebadged Sangean ATS909. It turned up totally dead and took me a fair while to track down what was wrong with it. www.paypal.com...
Great couple of videos Graham. I got one of these sold as spares or not working for £15 from you know where. Works fine after cleaning up the battery corrosion on the contacts. I think the way the aerial is hooked up with the white wire going to the board is poorly designed. Hardly any space for that wire and I noticed it rubs against the PCB. It also double backs on itself where it's screwed in with the washer. It looks like the constant pulling up and down on the antenna to extend it has resulted in the wires breaking on mine. It could well explain why so many people say the performance of this radio is very poor on the whip. With the wire making good contact I found it matched my Tecsun PL-660 on the whip. I snipped the mute wire to put an end to the dreaded mute on tuning sound. Excellent radio.
Thanks for you kind comments and glad you enjoyed the videos. I agree. This is a lovely radio and made by Sangean. I have another one here which I must get out and have a look at. I have a Tecsun PL-880 here which is really good but not noticeably much better than the R861
@@Radiocruncher I have the PL-660 but I think I'd much prefer the 880 out of the two.The 660 is a very good performer but I don't find it fun to use. Horrible buttons and interface. Last week I picked up the 909's successor, the ATS-909X. What a gorgeous looking radio and lovely to operate. They retail for £220 but I managed to snag a refurb from Sangean's EU store for £98 delivered. Bargain!
That was a bargain!
Sangean makes/made some Radio Shack radios as well...I believe starting in the 90's(?). Is your signal tracer probe home made? ~Jack, VEG
Well spotted Jack. This in RadioShack form is the DX398. One to look out for. Thanks for watching. Graham
And the signal tracer is homemade
At a guess a lengthy recap Graham. Looks a nice radio
Hi Simon. It's a great little radio and certainly sounds good. You may be surprised at what the problem was. Part 2 coming soon. Thanks for watching
I used to have a Sangean ATS909, the detector died in 2016, just after I retired, and Sangean's agent in Melbourne could only get a garbled response from Japan about noise levels in the users home. CanOhm ( the Australian agent) did a deal on the ATS 909x, the DSP model, at half price. Nice radios although the 909x has an AC wall adaptor. No reason why you can't use DC though, just needs to be a little higher volts to allow for the diodes.
Shame yours died but great deal on the 909x. I think 909 and 909x are very similar. I did manage to get an AC adapter but all will be revealed in part 2. Thanks for watching
Very similar appearance wise, the X has full RDS not just station name and time. Tuning knob on the front has the step button in the centre but the knob is a mechanical encoder not photointerruptor. Can false trigger. Up and down buttons on the left. More memories. DSP tends lower noise level as signal disappears. Has the same I2C bus holes on the bottom. Yes that's I2C bus, some hackers have figured out how to load the memories from a PC :)
The x version certainly seems to have the edge. I did wonder what those holes in the base were used for. Thanks for the info
Hi Graham - If you have a spare moment I wonder if you could maybe point me in the direction of how to fix an issue with my R861 please. I recently acquired it for peanuts and the batteries had leaked over time. I cleaned that up and it has been performing great. What a wonderful radio. On a few occasions it has started emitting a piercing screeching noise. So loud I have to switch the radio off. This only seems to occur a few seconds after the radio has been turned on and doesn't happen all the time. The occasions it has happened the radio hasn’t been switched on for a while. Typically last thing at night and first thing in the morning. I’m fine at soldering but my knowledge of electronics and fault finding is minimal! Thanks for your time.
My hunch is the speaker is on its last legs. The stock speaker on the ATS-909 is notorious for failing and going out with a bang. Instead of recapping the radio I thought it would make sense to try the speaker first. I ordered a replacement from Ebay for a fiver. The stock speaker is a 77mm 8 ohm 3w. I could only find a 1 watt equivalent. Soldered it in today and all seems good so far. I shall report back with an update after longer listening. If anyone has this radio then take a look at the ultimate ATS-909 resource. Some great stuff www.davidmoisan.org/radio/sangean/ats909faq.html If it does turn out to be the speaker then it seems Sangean continued using these speakers long after the initial release of the radio in 1996. My speaker is stamped 2005. I'll leave all this here as it may help someone else in the future.
Yes it was the speaker. Had the new one in for several days and no more awful screeching noise.
It took me. While to reply to your comment and you have already diagnosed and repaired it so well done. I’ve heard of the speakers failing in these before but not experienced it myself yet
@@Radiocruncher I spoke too soon. It's back. Arrrggghhh!
Have a look at the voltages around the output stage and check the capacitors
Looks fun..!
It certainly was. A bit out of my comfort range. Thanks for watching