AM Antenna Swivel Mount

LBPete

Rolling Along
Subscriber
This past year I've accumulated 6 Sansui Receivers, an 8080, an 8080DB, two 9090s and two 9090DBs. 4 of the 6 have broken AM antenna mounts. This is the plastic clam shell that holds the ball end of the AM antenna.

In looking pictures of these receivers on Ebay, it looks like more than half of the 8080/9090 class receivers listed have the same problem.

Is anyone making a reproduction mount? It looks like a pretty simple part. If no one is currently reproducing them is there enough demand to make it worthwhile?

Is this same mount used on other than the 8080s and 9090s?

- Pete
 
Famous vintage receiver failure... dummy owners think it's a rear handle to lift the receiver for moving, dusting, etc. :eek:

Needless to say the rated strength is not quite up to that task :p:

I know of no replacement source..sorry

Lefty
 
I'm looking into getting these antenna mounts reproduced. I've sent pictures to a couple of plastic molding companies to try to get estimates. There is a major cost for the dies that form the parts. Once the dies are made, the cost per part is relitively small. I'd like to break even on the deal but to do so, I'm guessing the cost per mount assembly would be in the $15 to $20 range.

Any comments?

- Pete
 
LB, I was thinking the same thing, the 7070 and I think the 6060s use the same mount.

I was thinking of maybe having someone machine them out of aluminum and black anodizing them.

Maybe we should get together and make some plaster molds and make our own.
 
I repaired my antenna mount by drilling a hole on each end of the socket bracket. Two holes in each bracket half.through the crack and into the main part of the bracket. I used a small drill (about .028") held in a pin vise, to drill the holes.I put some shallow holes (1/16 deep) on the surface of the fracture, to provide additional surface area for the adhesive. I cut some straight pins (depth of hole) to about 3/4" long. I slid the pins in part way, to locate the broken top piece. Then a small dab of epoxy placed on the parting line. Squeeze the pieces together, push the pins in all the way, and clamp. Wipe off any epoxy that squirted out and let it cure. Once cured, polish the crack line with 2000 grit paper and platic polish or semichrome, Brasso. Blacken the exposed pin heads, and you could hardly tell that it's been repaired.
 
REK, The problem that most of us have is that we don't have the broken pieces. The units come to us with the mount broken and the pieces missing.
 
CDFixer, If you don't have all the pieces, maybe having one machined is the way to go. If you were to have it machined slightly oversized, (shrinkage when casting) then you could use it as a master, to make a silicone mold. Then cast them with a black resin. LBPete is right about the HIGH cost of machining a plastic injection mold to make the mount, especially if the mold were designed to make both halfs with the mounting holes and socket for the ball end. The mold would be cheaper to machine, if it were designed to make the whole mount in one piece. The mount "blank" could then be drilled for the mounting holes, cut in two, and each half machined with a ball-end mill, for the socket.
 
Lefty,
Yes some people use the antenna for a handle. I've seen pictures on ebay with the antenna ripped out by the roots. I don't think that is the typical failure mode though. In looking at these things, I think they fail because they are over tightened. The mount is made in halves. The halves are identical and are held together with a small through bolt. The through bolt controls the tension placed on the antenna ball. When tighten until it is snug, the two halves don't quite come flush together. If tightened past that point, the halves will come flush but there is a lot of stress placed on the ball socket. Over time, if the antenna is moved, the ball sockets can crack and eventually separate.

To prevent the mount from breaking, loosen the the two hold down screws and the trough bolt. Put a little silicon spray on the ball and tighten the through bolt until the ball is held but still rotates smoothly. Then tighten the mounting screws. That will make it move smoothly and relieve the stress.

rek50,
If I had the broken pieces, I might try the repair you outlined, but like CDfixer, all I have is stubs.

CDfixer,
Although the idea of machining these things out of aluminum is appealing, but I don't have access to anyone to do it. I'm sure the cost of paying someone to machine one would be pretty steep. Besides, I need 4 sets. I don't think the 6060 uses this mount but some of the tuners of the era do. In scanning ebay, it looks like the TU 217, 317 and 717 all use it.

I don't know enough about the casting process to comment on plaster or silicon molds. I do have the first estimate to get these things made professionally. The mold alone is about $1,200, and it is considered a low cost low volume mold! I should have another estimate from another supplier this week.

These estimates are to make exact copies of the originals using the same or better material. These molds have a useful life of about 2,000 pieces. Once the mold is made, the per piece cost is totally dependent on the number made at one time and the material used. It takes two pieces to make one assembly.

I know from looking at ebay auctions, there are a lot of broken antenna mounts out there. I'm willing to step up and get the molds made, but I don't want to be stuck with a couple of boxes of unwanted mounts and an empty wallet. To make it work, I'm still estimating $15 to $20 a mount. I need 75 to 100 takers to break even. Are there that many takers out there or am I nuts?

- Pete
 
AM antenna mounts

Hey,

The TU-919 also takes this mount, as do all the the TU-x17/x19 series tuners AFAIK.

I would definatley be interested in picking up a few of these mounts if you decide to have repro's made. $15-20 a shot isn't too bad, I would buy at least three, possibly more so long as the price stays in that range.

FWIW, if you front the cost of making these, I would think you could sell them on ebay, and get a fair number of sales. After all, the "special tool guy" was selling 75 cent allen wrenches for 10+ bucks a shot, and this part is nowhere to be found now as NOS, so you'd have the market cornered.

Hope to see you do this, if you find the demand is there to justify the initial cost.

I considered this myself about 3 years ago, but didn't feel I could recover the investment at the time. Now, with this forum and the fact that interest in vintage gear is way up, it might be doable without losing money.

Regards,

Kevin
 
Milling out of ABS

If someone can send me a drawing with dimensions I can mill one out of solid ABS or any solid plastic. When its finished I can post a pic of it and you can let me know what you think.
 
Mzimm,
I don't have drawings, and my drawing/drafting skills are limited to stick figures. Thanks anyway. These things would actually be complicated to machine. There is a good deal of detail in them. For example, there is a locating peg and it's corresponding socket cast in.

The second estimate for the mold was substantially higher than the first. It's for a more traditional and much longer lasting (100,000 or more parts) aluminum mold. It would be cad designed and make a more accurate part too. They have a much lower per piece cost to manufacture which somewhat offsets the higher mold cost, but they also want a 90 day lead time.

So, I'm still on the fence. The second estimate complicated the decision.
 
Injection Molding

I could also make tooling (mold) and have access to a small single shot plastic injection molding machine. I could mold these out of delrin, acetel or nylon. I do have a Sansui with this antenna mount but I want to be sure its the right part. How large of a demand is there for these?
 
mizmm,
I'm trying to determine the demand for this part. My guess is there are hundreds of broken ones out there.

Here is a picture of the part. The photo looks a little washed out because I had to tweak it in PhotoShop to get the detail of the black part to show up. It takes two of these to make one mount.

If you were to make a mold, how hard would it be to make a couple of hundred pieces?

- Pete
 
If I were to make a mold, making a few hundred parts would be very easy. Once the mold is made if there is a future need for this part it would just require setting up the molding machine and shoot another few hundred. What models does this mount interchange with?
 
I'm definately in for 2 or 3 LBPete. I have a 8080DB with a broken mount. Always good to have a couple more around in case I go off and buy more vintage Sansui's.
 
Originally posted by mzimm
If I were to make a mold, making a few hundred parts would be very easy. Once the mold is made if there is a future need for this part it would just require setting up the molding machine and shoot another few hundred. What models does this mount interchange with?

Mzimm, if you are interested in doing this, I'll PM you and work out the details. I am also pursuing other leads.

- Pete
 
Back
Top Bottom