2 question for the Kenwood TS530SP

Discussion in '"Boat Anchor" & Classic Equipment' started by KB1FGC, Nov 8, 2021.

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  1. KB1FGC

    KB1FGC Ham Member QRZ Page

    Hello All.I wanted to complete my boat anchor collection by getting a Hybrid rig.I'm cleaning it up right now.Most of the front knobs came off,but I didn't realize the Band switch knob was secured with a hex bolt.I tugged maybe a little to hard and was hoping I didn't do any damage to the switch.The shaft pulled out a little bit so pushed it back in.The knob doesn't have a detent at all,Is that how it's suppose to operate?
    Also, The large tubes in back,Do they pull out?It has a large metal band around the base.
    Thanks
    73
    Rich
     
  2. K7TRF

    K7TRF Premium Subscriber QRZ Page

    You likely did not damage any of the band switch wafers as during disassembly that shaft actually pulls right out. I would double check that the shaft is fully inserted into all the wafers including the band switch wafer inside the finals cage. And yes that band switch should have a solid detent at each band position.

    The final tubes do pull up and out of their sockets, don't pull on the metal anode cap as that can come free but gentle pulling and wiggling of the tubes should get them free.
     
  3. KB1FGC

    KB1FGC Ham Member QRZ Page

    Thanks for that.I was looking at the wrong components.The 2 large components that I see are what look like the filter caps for the rectifier in the power supply.I realized that later when I removed the cover and saw the the tubes.Hayseed Hamfest doesn't have recap kits for the TS530.I have no idea if the components are original.Are those large canister caps easy to find?If not I'll leave them in for now.
    73
    Rich
     
  4. K7TRF

    K7TRF Premium Subscriber QRZ Page

    Yeah, the HV caps aren't hard to come by, there are ebay sellers that stock those or they can be easily sourced from Mouser, Digikey, Newark or other component houses. If you change them, check the diameters of the replacements as they're often smaller diameter than the originals. Most folks that sell replacement kits include the correct size clamps if the new caps aren't the same size as the originals.

    [edit] Tip, if you do replace the HV caps it's a good idea to cover the exposed metal on the top of the cap near the finals cage with a layer or two of electrical tape. The two caps are in series to filter the HV supply and the case of that cap near the HV cage is up at roughly 400V so when you do things like make adjustments in the rigs it's all too easy to accidentally touch that capacitor case and get a nasty shock. For that matter even if you don't replace the caps if you're seeing the metal case of those caps exposed it's a good idea to insulate the one that's up at +400V.
     
    Last edited: Nov 8, 2021
  5. KB1FGC

    KB1FGC Ham Member QRZ Page

    Thanks the tip.I looked at the band switch shaft and it looks like the coupler is not connected to the shaft that is in the high voltage cage.The problem is,Is there an easy way of getting to the shaftThanks
    Rich
     
  6. K7TRF

    K7TRF Premium Subscriber QRZ Page

    It's not too bad, just open up the HV cage and though it's tight in there it's not too hard to reattach the shaft coupler. Always discharge the HV caps with a 'chicken stick' (basically something like an insulated screwdriver with a clip lead from the blade to ground) before reaching into the HV cage. If the rig hasn't been plugged in for a long time that's not a huge concern but it's very good practice and easy insurance to always discharge the HV caps either at the caps or at the anode caps for the tubes before reaching into the HV cage and of course the rig should be unplugged.
     
  7. KB1FGC

    KB1FGC Ham Member QRZ Page

    Thanks again.The rig has been off for a while.I just got it 4 days ago.The guy I think hadn't had it on for a long time.I agree with you though.Better to discharge.One concern that I have is,The caps that are in where the large tubes are,That is so tight in there.I put my DMV on it and there is pretty no voltage.Luckily the larger caps were easiest to get to.But there were some smaller ones I couldn't reach.I couldn't even measure the larger ones until I took out the tubes.I was real carful taking the tubes out though.I would of never done that had the rig been on within the last couple of days.I did check the large caps that are in the plastic housing and they have no voltage on them.Also the bleeder resistors looked correct or at least had a lot of ohms across them.I couldn't read the marking to well and have to check the schematic to double check that they are OK.
    73
     
  8. K7TRF

    K7TRF Premium Subscriber QRZ Page

    It's generally not necessary to measure the exact value of any of the capacitors in the RF finals cage or the bleeder resistors on the HV caps. Sure no real harm but you basically test that circuitry (the caps in the finals cage) by seeing if the rig loads up properly on each band per the manual. IOW, if there's a major error with one of the RF capacitor values it will show up by not being able to get an appropriate plate current dip or inability to load up the finals properly (though that can also be other problems like soft tubes).

    If you do end up having trouble getting proper power out of the rig (a tad over 100 watts on all bands except possibly 10m) they do sell finals cage rebuild kits that include components like cathode and screen resistors, a bypass cap and an RF choke that sometimes goes bad. The cathode resistors in particular are common problem areas and are worth measuring (should measure 5 ohms from any one of the cathode pins to ground as all the cathode resistors are in parallel). But I've never really gone through the process of trying to measure capacitor values for those RF cage caps as it's easy enough to test them functionally by looking for a plate current dip on each band without having to go to an extreme on the Plate control.

    There's a lot of really good information on the Kenwood hybrids on the web including some on the late K4EAA's site: https://www.k4eaa.com/about.html

    Or here: https://www.hybridrestore.com
     
    WD5GWY likes this.
  9. KB1FGC

    KB1FGC Ham Member QRZ Page

    Thanks so much for the webpages.I see they sell a recap kit!
    73
    Rich
     
  10. K7TRF

    K7TRF Premium Subscriber QRZ Page

    They do, but a word of caution. If the big electrolytics are original or if you have clear problems with HV or supply filtering it can make sense to replace the HV caps, the screen caps and potentially the larger electrolytics in the supply section. But unless you have known troubles with the smaller electrolytics on the Audio, IF or other boards it's a big undertaking to recap the whole rig and those early PCBs that Kenwood used in the hybrids are easily damaged in that it's very easy to end up lifting traces in those first generation PCBs. So unless I have symptoms that tell me the rig really needs new caps or can obviously see blown caps (the audio board is a common place for that) then I generally don't recommend a full recap of the entire rig.
     

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