UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Kenwood TS-520SE Transceiver overhaul notes Pt1

David G4EBT · 12th May 2019, 7:17 pm

The Trio TS830 is a spendid rig which was deservedly popular, especially with contesters, in its heyday. Excellent both on receive and transmit. (superb on CW with the CW filter fitted). I bought one new in 1986, though lost interesit in amateur radio some years ago so I sold it, along with the matching AT230 ATU, (which will tune just about anything), the filtered speaker, the Low Pass filter, and HS5 'phones.

The TS830 sold really well for some years and they often crop up at rallies at very reasonable prices. Now more than 30 years old, so it's not surprising that some common faults and shortcomings have arisen, including the bandswith shaft coupler, but it's not difficult to fix.

There’s a picture of the original flexible plastic shaft coupler here, which illustrates how they fail over time:

http://www.lz5zm.com/kenwood-ts-830s...s-replacement/

Ken K4EAA in the USA, has specialised over the years in the repair of Kenwood TS-520, TS-520D, TS-520S, TS-520SE, TS-520SP, TS-820, TS-820S, TS-530S, TS-830S, R-820. He outlines the procedure for replacing the coupler with the least amount of hassle here:

https://www.k4eaa.com/couplers.htm

There’s also a youtube video here:

https://www.youtube.com/watch?v=sQV4Lt-fIy8

The original flexible plastic couplers were 15mm diam x 15mm long, fixed with four Allen screws. To remove the old coupler requires a long 1.5mm Allen key. EG:

https://www.ebay.co.uk/p/Draper-1-5m...d=323327230217

There seems no reason that the coupler has to be flexible or made of plastic. K4EAA can supply custom made rigid brass couplers which are smaller in diameter than the originals to makes replacement easier. (He can supply other parts too):

https://www.k4eaa.com/parts.htm

However, for customers in the UK, when shipping is added the cost is probably prohibitive. For anyone with access to a metalworking lathe it's not complicated to make replacements but 6mm shaft couplers can also be found on ebay, though usually with only one securing screw at each end rather than two. Flexible metal couplers for 6mm diam shafts are also available from a UK supplier but they’re 25mm long x 20mm OD:

https://www.ebay.co.uk/itm/254180503911?ul_noapp=true

Flexible plastic couplers for 6mm diam shafts (size of coupler 22mm x 15mm) are available here from a UK supplier:

https://www.ebay.co.uk/itm/6x6mm-CNC...wAAOSwW4tcRb05

A couple of other videos that might be of interest and help are here:

Adjusting the coil packs Kenwood TS hybrid transceivers with uneven receive/transmit peak on drive control:

https://www.youtube.com/watch?v=AAk5_LE5UF4

How to tune up the PA:

https://www.youtube.com/watch?v=bTVpQ18dn1o

Scores of mods, hints, tips and repair advice on the TS830 at mods.dk here:

https://www.mods.dk/index.php?ModelI...ioId=1-kenwood

Hope that's of help and interest.

12th May 2019, 7:17 pm	#16
David G4EBT Dekatron Join Date: Feb 2003 Location: Cottingham, East Yorkshire, UK. Posts: 5,761	Re: Kenwood TS-520SE Transceiver overhaul notes Pt1 The Trio TS830 is a spendid rig which was deservedly popular, especially with contesters, in its heyday. Excellent both on receive and transmit. (superb on CW with the CW filter fitted). I bought one new in 1986, though lost interesit in amateur radio some years ago so I sold it, along with the matching AT230 ATU, (which will tune just about anything), the filtered speaker, the Low Pass filter, and HS5 'phones. The TS830 sold really well for some years and they often crop up at rallies at very reasonable prices. Now more than 30 years old, so it's not surprising that some common faults and shortcomings have arisen, including the bandswith shaft coupler, but it's not difficult to fix. There’s a picture of the original flexible plastic shaft coupler here, which illustrates how they fail over time: http://www.lz5zm.com/kenwood-ts-830s...s-replacement/ Ken K4EAA in the USA, has specialised over the years in the repair of Kenwood TS-520, TS-520D, TS-520S, TS-520SE, TS-520SP, TS-820, TS-820S, TS-530S, TS-830S, R-820. He outlines the procedure for replacing the coupler with the least amount of hassle here: https://www.k4eaa.com/couplers.htm There’s also a youtube video here: https://www.youtube.com/watch?v=sQV4Lt-fIy8 The original flexible plastic couplers were 15mm diam x 15mm long, fixed with four Allen screws. To remove the old coupler requires a long 1.5mm Allen key. EG: https://www.ebay.co.uk/p/Draper-1-5m...d=323327230217 There seems no reason that the coupler has to be flexible or made of plastic. K4EAA can supply custom made rigid brass couplers which are smaller in diameter than the originals to makes replacement easier. (He can supply other parts too): https://www.k4eaa.com/parts.htm However, for customers in the UK, when shipping is added the cost is probably prohibitive. For anyone with access to a metalworking lathe it's not complicated to make replacements but 6mm shaft couplers can also be found on ebay, though usually with only one securing screw at each end rather than two. Flexible metal couplers for 6mm diam shafts are also available from a UK supplier but they’re 25mm long x 20mm OD: https://www.ebay.co.uk/itm/254180503911?ul_noapp=true Flexible plastic couplers for 6mm diam shafts (size of coupler 22mm x 15mm) are available here from a UK supplier: https://www.ebay.co.uk/itm/6x6mm-CNC...wAAOSwW4tcRb05 A couple of other videos that might be of interest and help are here: Adjusting the coil packs Kenwood TS hybrid transceivers with uneven receive/transmit peak on drive control: https://www.youtube.com/watch?v=AAk5_LE5UF4 How to tune up the PA: https://www.youtube.com/watch?v=bTVpQ18dn1o Scores of mods, hints, tips and repair advice on the TS830 at mods.dk here: https://www.mods.dk/index.php?ModelI...ioId=1-kenwood Hope that's of help and interest. __________________ David. BVWS Member. G-QRP Club member 1339.