KWS-1 Rehab

Discussion in '"Boat Anchor" & Classic Equipment' started by W5INC, Dec 24, 2018.

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  1. W5INC

    W5INC Ham Member QRZ Page

    So I did finally get around to the KWS-1 that has been sitting idle for a while here at the QTH. The HV filter choke is in transit to get rebuilt and it was time to get to the PA loading and tuning sections which weren't as smooth as silk when turning the pieces. These controls have to be smooth or you will FUBAR up the PA loading and tuning knobs, which I acquired separately from the Xmtr. These knobs are close to unobtainium and cost me a few dollars to buy, so I sure don't want to screw them up.

    Getting the PA section out was a chore if you never done it before and is still a chore even if you have. The PA section had/has insulation glued onto the bottom of the PA tube floor compartment and that was ate up by rats it looked liked. So another reason to take out the PA section. The PA section is out and I gave the roller induction coils a good cleaning using 91% Isapropyl alcohol only so as not to cause any unnecessary problems when it goes back together. The rod that the roller wheel is mounted on was gunked up with a black susbstance and the alcohol took care of that. Next up will be little Singer sewing machine oil used to lube up the gear wheels a touch to see if these tuning sections can be made to work like grease lighting again.

    I would like to keep everything together in this endeavor as much as possible, but if the gears do need to come off, to get everything working smoothly again, what is the best way of synchronizing the air caps and roller induction coils, so they are in the proper position to work when put back together? I have looked around and I have found nothing on this via the web so I have come to the true boat anchor resource QTH, here in the Zed forum. Everything looks good on the gears, so once everything gets lubed up again, the PA tuning and loading knobs should turn just like they did when leaving the factory 60+ years ago. As always, any help is greatly appreciated by the real BA techs here in this Forum.
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  2. W5INC

    W5INC Ham Member QRZ Page

    Taking out the PA section of the rig, the aluminum extension rods have a lock collar on them so the rods don't come out of the front of the radio. This lock collar has 2 tiny set screws on each collar and the hex screw is stripped out on 1 side. The collar can't move in this position so the set screw will need to come out. I have no idea where to get a set screw that is that size as a replacement. The Allen head wrench that is suppose to fit that screw is labeled as a .05 Allen wrench that is the next size under a 1/16 Allen wrench. I have let them soak in penetrating oil all last night and I will see if I can remove it today somehow. bangHead.gif

    I found the list of the deadly caps that should be changed out in the KWS-1 and the list follows. I haven't scoured the KWS_1 manual as of yet, but a quick glance does indicate the BB caps are on that list along with the blue caps that are right close to the BBs that need to be replaced. Here is the list of the caps that should be replaced.

    C-325 .0033uf @400V

    C-324 .47uf @400V

    C-403 .1uf @200V

    C-413 .1uf @150V

    C-113 .01uf @400V

    C-115 .01uf @400V

    C-122 .001uf @400V

    C-127 .1uf @150V

    C-134 .1uf @150V

    C-303 .033uf @400V

    Power supply cap C-506 .22uf @400V

    Then there are blue capacitors in the audio section that need to be replaced

    C-116 .5uf @200V

    C-114 .2uf @200V

    C-106 .5uf @600v

    Last edited: Dec 25, 2018
  3. W5INC

    W5INC Ham Member QRZ Page

    This is the bottom hatch cover of the air cooling chamber that sits right under the PA tubes themselves. The insulation was in pieces chewed off by field mice, I am guessing here. So this old insulation that is left on the hatch will be scrubbed off, with the surface cleaned with alcohol and a razor blade to get the old adhesive off. I don't know what type of insulation I will be going back on this hatch piece but it sure won't be the old fiberglass stuff, that was on the piece originally. Maybe some Lizard Skin ceramic coating on the piece, instead of the old paper fiberglass insulation type? The ceramic coating is good to 500 degrees F, which should be good enough for this application, I reckon.

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  4. WB2GCR

    WB2GCR Ham Member QRZ Page

    Collins decided to get rid of the insulation entirely.
    It was for noise not thermal considerations, afaik.

    Did yours function at all before you started taking stuff apart?

    I have a thread up a few months old now, regarding the 1st mixer, 250kc osc + PTO,
    which does not function on mine. :(

    Haven't had a chance to run a signal generator through and see what is NG and what is good
    yet. Thus far have found nothing much "wrong" but it must be something!

  5. W5INC

    W5INC Ham Member QRZ Page

    Mine came with a bird's nest inside of it, Mr. Bear. It was stored inside of a large outdoor super nice workshop, sitting on 14 acres and the property is very close to a river. So wildlife was very abundant. Most of the pieces were there and I have been gathering the pieces that weren't such as the PA tuning loading knobs, original T/R relay setup, assorted tubes and a few other pieces needed to make the package work once again. I don't want problems with the tuning sections in the PA compartment so that was the reason for taking out the entire PA unit as the bird's nest was parked right there over the tuning coil shafts. This unit could be considered a basket case but I have always wanted a KWS-1 so here it sits. As my Dad once told me, "Son you Always get to be careful for what you ask for, as you might just get it." The price was more then right and since there aren't many of these units around working anymore, seemed like the thing to do. I am more then happy the Xmtr and PS are here at the QTH. The Xmtr is stamped #1041 so it is a later unit out of the 1600 or so KWS-1s Collins made.

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  6. KG7HVR

    KG7HVR Ham Member QRZ Page

    Paging alex k6afs
    He knows these radios.
  7. W5INC

    W5INC Ham Member QRZ Page

    Getting the PA cage apart was a major task, because I couldn't get the idler gear for the big Baker-Williamson tank roller inductor and air cap removed. The PA cage can only be taken apart when the top 2 air caps are removed from the unit, allowing you access to the bolts, nuts and screws holding the sheet metal together. The top air cap gear has to be rotated, so the holes in it's makeup can be accessed to remove the cap itself from it's mounting perch. Since I couldn't rotate the unit and didn't want to FUBAR things up, I need to take off the circuits idler gear setup. Getting to the nut on the idler gear required using a long skinny needle nose pliers that was a PITA to get in there in the needed position. Once the idler gear was removed I could now work on getting the big tank roller inductor freed up along with the air cap. The air cap's main shaft has a screwdriver slot in it, as a way to turn the shaft when needed. Some synthetic sewing machine oil was used for the oiling job and I will be working it in by turning the unit by hand many times here in the next few days. It now moves freely with no binds. I like to hand turn these pieces to feel if/when any binding of the parts take place.

    This Xmtr was probably used on only 1 band by the previous owners. There is no wear on any of the gear cogs and they are still sharp as the day there were made. The big roller inductor is very stout to say the least and is a beast to turn with just the little gear on the main shaft, using just your fingers. The shaft where the roller inductor wheel traverses has some crud on it and I tried to clean it up with Alcohol. It took some of the crud off. I will now put a light coat of sewing machine oil on it and crank the wheel up and down a few times to get the shaft clean once again. After this is done I can remove any oil that is left on the shaft using Alcohol. Even when the pieces are lubed up correctly, the tune side inductor and air cap will still take some major effort to adjust them. This rig was built like a tank to say the least. Real American IRON. :)

    I found this piece here in SB VI for the KWS-1. It is the method to align everything up in both tuning circuits via the 3 air caps and 2 roller inductors used in the tune loading circuits. There are actual stops on the roller inductor coils, so I will be using those stops as the benchmarks to line up roller inductors to be in the correct position when everything is put back in place. Just making sure that this procedure here wasn't updated.

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  8. WB2GCR

    WB2GCR Ham Member QRZ Page

    Ok, well I did not need to remove mine. They are sealed.
    Guess Mr. Mouse got in anyhow...

    On mine, iirc there were Bristol Spline set screws.

    I have some subchassis with parts, some could possibly be liberated.

    Do you have the turns indicators for the front panel??
    Those are tough and tricky to fix or to find.
    You need to be very judicious with tightening the setscrews.
    I put a write up on them in an earlier thread, if you want the pdf, email me?

    Fwiw, I use synthetic lube after things are degreased.
    Right now I'm favoring the heavy synthetic automotive gear oil.

    Personally, I'm concerned about the HV connector.
    I intend to change mine to a HV BNC and route the HV through good
    quality RG-58 (with solid dielectric). I'd prefer a "reverse" BNC, but
    I've not seen where they make that...

    The one on mine is one of those blue connectors with a single pin, like the
    ones used in R-390A and other gear. It's worrisome to me at 2kV.
  9. W5INC

    W5INC Ham Member QRZ Page

    My scrap heap find didn't come with the turns indicators Mr. Bear. I read your very detailed article on repairing those turn indicators which I have saved into the knowledge vault. When seeing how 1 of the extension rod's old brass couplings was actually cracked by someone trying to turn the "frozen" air cap/roller inductor setup, along with your write up, I decided to pull the whole PA section out of the unit. There is a hair line crack on the coupling that will probably get epoxied up as I sure don't want to try brazing that piece to repair it.

    I have found the turn indicators which weren't cheap and they are in very good shape. Just a word of warning here there looks to be 2 different thread counts on the locking nuts for the turn counters. 1 is a little finer thread count then the other and the 2 won't match up it looks like. I have also garnered the original T/R switch setup with all of the original cables and relay. These are in perfect shape and I got lucky to find them. This KWS_1 resto project is like a boat, lot cash in and not much cash out. :)

  10. WB2GCR

    WB2GCR Ham Member QRZ Page

    I'd look very very closely at the shape of the hole that the shaft goes into... per my post.
    Also at the little gear that rides... you need both the outer part (knob) and the inner part
    that mounts on the chassis. Did you get both??

    Also, I'd wash most of the radio - good idea to keep water and cleaners 100% OFF the drum dial.
    Out of the meters. Other than that, it can wash pretty well...

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