Bush DAC10 - MW Frame Aerial
 

Currently restoring another Bush DAC10 but this one seems to have lost the windings for the MW Frame Aerial.

Attachment 216157

I'm hoping someone may have an intact spare that I could acquire otherwise I'm going to have to contemplate rewinding!

All costs including p&p will be covered so PM me if you can help - thanks.

Re: Bush DAC10 - MW Frame Aerial
 

I think it's the same as a DAC90A frame aerial, so if someone can count the turns you could rewind it. I did one and it's not as difficult as you might think. Just requires a steady hand and a bit of patience. I think it's only 20 or so turns - don't quote me! But it's not dozens and dozens. Exact wire gauge isn't too important, but too thin is hard to handle and too thick and they won't lie nice and flat on the rim.

If you can, make a drawing of what's left on how the ends go through various holes in the plastic disc and attach to solder tags. It might matter which direction you wind it, if it's in series with the LW coil - I can't remember off hand.

Re: Bush DAC10 - MW Frame Aerial
 

Thanks Ian - I think it will end up being a rewind job.

Assuming that acquiring a spare, intact frame aerial may be a bit of wishful thinking on my part I'd need advice on the following along with the points raised in Ian's Post above:-

1. Which gauge and type of wire would be best?

2. A reliable source for the wire?

3. Would the set then need to be re-aligned?

Re: Bush DAC10 - MW Frame Aerial
 

Hi Donald, I think the wire used is about 0.2mm dia, easily obtained from wires.co.uk in small quantities, En Cu is fine. A coat of a low tack adhesive on the former will assist wire placement.
Alignment should not be that far out, but will probably need a tweak.

Ed

Re: Bush DAC10 - MW Frame Aerial
 

Thanks Ed - a bewildering choice of wire at wires.co.uk!

Would this wire be suitable: -

50g 0.212mm Solderable Enamelled Copper Wire
Ref: SX0212-050

https://www.wires.co.uk/acatalog/SX_0190_0280.html

Re: Bush DAC10 - MW Frame Aerial
 

Hi Donald that should do nicely, but note that the wire diameter given is the copper size, not the overall size.

Ed

Re: Bush DAC10 - MW Frame Aerial
 

If it's any help, I have a DAC90a on the bench - the MW coil is 22 turns of 0.31mm OD with a dc resistance of 3.2 ohms

Re: Bush DAC10 - MW Frame Aerial
 

Thanks Ed - I've noted that the copper size is 0.212mm 35 SWG which is not the OD.

Thanks Shuttle - extremely helpful.

Can you advise which way the wire is wound around the former i.e clockwise/anti-clockwise and starting/finishing at which tags?

Re: Bush DAC10 - MW Frame Aerial
 

Hi Donald, 0.31 coated is 0.25 bare, so 0.212 shouls be fine

Ed

Re: Bush DAC10 - MW Frame Aerial
 

The MW coil in my DAC90a is wired anticlockwise from Tag B (common point of LW/MW coils) starting closest to you (looking from the RH side of the chassis as in the picture A) and ending in Tag C nearest the chassis. If you need any other pictures just ask. The closeup shows how it is terminated. The DAC10 should be similar, the part no. is different but the MW coil is about the same resistance, so I'm guessing they only changed the LW coil slightly.

Arthur

Re: Bush DAC10 - MW Frame Aerial
 

Wire ordered from wires.co.uk - thanks Ed.

Shuttle - your instructions are excellent so thanks for taking the time to respond.

Re: Bush DAC10 - MW Frame Aerial
 

Rather than opening a new Thread I thought I'd just append to this one for advice on obtaining suitable 16μF and 32μF electrolytics to replace the large dual can. Moderators please move if required?

I know that modern dual cans can be obtained from the BVWS but this isn't what I require this time round.

The existing dual can is missing from this DAC10 but I have one from another set that I intend to restuff - my first time! I'll Post details of my restuffing later but things are going very well so far! :)

I just can't find a source for electrolytics of a suitable capacitance and voltage??

Re: Bush DAC10 - MW Frame Aerial
 

For some years I've used Rubycon miniature capacitors from Farnell, which - though small - have a high ripple rating and are 105 degree C rated.

They're available in a wide range of values and voltage ratings.

I mentioned them in this thread back in 2014:

https://www.vintage-radio.net/forum/...s+for+stuffing

From the data sheet you'll see that they often come in different shape formats - short and fatter or long and thinner.

These would probably suffice for your needs and fit into the old can:

450V 33uF 12.5mm diam x 25mm long:

https://uk.farnell.com/rubycon/450bx...c%20capacitors

450V 15uF 10mm diam x 20mm long:

https://uk.farnell.com/rubycon/450bx...c%20capacitors

Unlike many capacitors from other suppliers, these have detailed datasheets whereas too often, there's no clue as to ripple rating.

http://www.farnell.com/datasheets/2321299.pdf

They're so small that three can be fitted in a triple unit can as shown below.

Best of all, they're inexpensive and from a reputable supplier.

Hope that helps.

Re: Bush DAC10 - MW Frame Aerial
 

Thanks David - I know that you have previously recommended Rubycon miniature capacitors from Farnell and they seem ideal.

Order placed BUT I really baulk at having to pay a Handling Charge of £5.95 - what's that for? Surely part of their job involves handling products? ???

Re: Bush DAC10 - MW Frame Aerial
 

It used to be free P&P on orders over £20.00 - since then they've upped it to £30.

Under £30 it's £5.95 P&P for online orders by 'non-Trade customers' and free for 'Trade' customers.

I have an account with them rather than buying as a 'guest' but I always order enough to get free P&P.

It doesn't take too many capacitors to reach £24.05, and if get that far, I might as well order an additional £5.95 more items as it makes no sense to spend £24.00 and pay £5.95 P&P. I sometimes top up with 25uF 25V caps which are commonplace as cathode bypass caps in output stages of many valves radios and invariably are shot..

Re: Bush DAC10 - MW Frame Aerial
 

My 0.212mm 35 SWG Solderable Enamelled Copper Wire arrived today. :)

I've detached the Frame Aerial from the chassis (LW resistance is 5.1ohms) and have my detailed instructions from Shuttle (Arthur).

All I need is a recommendation from Ed_Dinning on which low tack adhesive to use on the Frame Aerial former?

Re: Bush DAC10 - MW Frame Aerial
 

Hi Donald, sellotape inside out works well as will PVA woodworking adhesive

Ed

Re: Bush DAC10 - MW Frame Aerial
 

Double sided tape? Too sticky perhaps.

Re: Bush DAC10 - MW Frame Aerial
 

Thanks Ed - fortunately I have both of those!

Why was I assuming something a bit more esoteric and expensive? ;D

Re: Bush DAC10 - MW Frame Aerial
 

After a lengthy diversion to rebuild other sections of this DAC10 I'm now back looking at rewinding the MW frame aerial.

A few questions:-

1. Does anyone have any plans for a cheap and cheerful jig that could be used for rewinding.

2. How important is the wire gauge and the number of turns as the new wire I have purchased seems slightly smaller than the original. Here's a close up picture with the new wire at the top and the original wire underneath:-

Attachment 217879

This is the new wire I purchased:-

Attachment 217880

3. Assuming that I manage to wind 22 turns onto the former (as advised by Shuttle) how would I test that this is correct for the DAC10 MW aerial?