Yeasu ftdx570 power supply capacitors

Discussion in '"Boat Anchor" & Classic Equipment' started by N9AXL, Nov 19, 2017.

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  1. N9AXL

    N9AXL Ham Member QRZ Page

    I'm restoring one of these units. I'd like to replace the power supply capacitors. These seem to be held on by clamps.

    I'd prefer to replace with the same style rather than wire in caps underneath.

    Does anyone know what style these are and where I could get replacements?
  2. G3YRO

    G3YRO Ham Member QRZ Page

    As with most modern components, electrolytic capacitors are much smaller these days (for a given value) . . . so you're unlikely to find any that will fit in the original way.

    What makes you think they need replacing? Yaesu used very high quality electrolytics in their equipment back in those days . . . the electrolytics in my FT101E and FL2000B are still all fine.

    Roger G3YRO
    Last edited: Nov 20, 2017
  3. N9AXL

    N9AXL Ham Member QRZ Page

    I just normally replace all electrolytics. These seem to be physically fine and the rig powers up. The only issue with this is I get a burning smell from the HV cage which I think are the coupling capacitors. That's an easy fix. So are just suggesting running this with the original ps caps until they give up the ghost? I figured if I ran this at 100 to 150 watts output it would be less stress.
  4. W9GB

    W9GB Ham Member QRZ Page

    Electrolytic capacitors can have multiple ”physical dimensions” (Diameter to fit clamp, Height to fit case, Lead spacing, and termination style) for the same capacitance value (uFd) and DC Voltage (VDC).
    The horizontal cylinder with Clamp are sold with Screw (mechanical to wire leads or PCB) or Snap-In terminals (solder to PCB or wires).
    CDE has an extensive selection of capacitors mfg in S.E. USA, sold by all major US electronics distributors (Digi-Key, Mouser, Allied, Newark).

    Radio Repair is 90% Research and Proper Parts Procurement:
    Radio Service Manaus and Parts Mfg. / Distributor Catalogs.
    Actual parts installation is the Easy Part — IF you have Basic VoTech “ Shop” skills mastered.
    Last edited: Nov 20, 2017
  5. G3YRO

    G3YRO Ham Member QRZ Page

    You can assess whether the electrolytics are OK by two methods . . .

    One is to look at the DC waveform on an oscilloscope (via a suitable resistor divider), to see if there's much ripple.

    The other way (if you don't have a 'scope) is to see how much the voltage drops under load.

    As I've often mentioned before, in my experience the electrolytics Yaesu used back in those days seem to go on and on!

    Roger G3YRO
  6. N9AXL

    N9AXL Ham Member QRZ Page

    Thanks. I will try that. As I said I have some obvious issues with the coupling capacitors I will be replacing. I also am looking at getting a better cooling fan than the stock unit. I'm thinking a larger squirrel fan might move more air quicker which might reduce the stress on the finals.
    As to the PS caps were those screw or snap in? I may not need them now, but I might lay in some for later if I need them.
  7. N9AXL

    N9AXL Ham Member QRZ Page

    The other issue here is someone along the way buggered the case screws top and bottom. A few of them I had to drill out. Any idea what the size is? I looked in my hardware store and none of the are the right size. They look like 1/8" screws with a 45 degree chamfer at the top.
  8. KA9JLM

    KA9JLM Ham Member QRZ Page

    I am like Roger, I replace only the bad ones.

    Cap checkers and O-Scopes are your friend. :)

    Shotguns can be too, I guess. I try not to use the shotgun method for radio repair.

    Have Fun.
  9. G3YRO

    G3YRO Ham Member QRZ Page

    I remember when I worked for the main UK Yaesu importer, asked Yaesu if we could have some replacement screws, as rigs we had in for repair or part exchange had the odd ones missing.

    They sent a huge box containing about a thousand of mixed types (foc) - every kind of case screw, bevelled, countersunk, etc, and in every different paint colour for all the different rigs !

    I got really fussy, and every rig I sent back out had nice new screws with no paint damage !

    But I'm afraid I have no idea what size the threads were, other than the fact they were all the same (regardless of the age of the model)

    Roger G3YRO
  10. W9GB

    W9GB Ham Member QRZ Page

    1.) METRIC: Eastern Asian manufactured products generally use METRIC, unless they are cloning/copying US design — then the SAE (English screws) are generally of poor quality.
    Automobile Parts Houses deal with this every day.
    I have seen many threads destroyed by Self-tapping screws, Drywall screws (“I had that available”), and cross-threading.

    2.) Ken, K4EAA and other radio amateur vendors sell case screw sets.
    Photo below: M4 x 8mm, Phillips Pan Head (machine screw)
    Thee are a small selection of sizes used, with M3 and M4 most common.

    3.) Good Hardware stores are essential for repair and restoration work.
    Within a 5 miles radius of my QTH, I have McMaster-Carr HQ / Midwest warehouse with “Will-Call” counter; Ace Hardware HQ and retail store #1 and #2 (50+ years in business).
    ZORO and ZORO Tools are subsidiaries of W.W. Grainger (Lake Forest, IL) Internet store.

    Even with these resources, I stock key “harder to find” parts (old USA mfg.) —
    because waiting 3-4 weeks for a repair part — from China — is not reasonable.
    Last edited: Nov 21, 2017

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