A question about a Madison upD858 early unit

[loosecannon]

C179 it is. I just changed one.

Checking my supplier, I'm finding tantulums have a premium cost to them. Are they worth 10x the cost over the same value in electrolytic? That's going to be a hard sell.

yeah Mike that is going to be a tough one. with a limited supply of tantalum left, the price is going to go up more, and probably never down again.

I can tell you that i have changed so few tantalums in the time i've been doing this stuff that can't even remember when the last one was. i think it was a C179 in an 858 chassis though! LOL
that one should have been an electrolytic from the factory.

I am by NO means an authority on tantalum caps, or any other cap for that matter, but if you are considering this; i would advise you to start diving deep into the subject online.

you will find some people that think they are the devils capacitor, and some who can't sing it's praises enough.
i can tell you this, i've re-capped quite a few radios, and i never replace the tantalums, and i've yet to have one come back with a blown cap.
not sure how objective that is, but it's all i got.

If it were me, i might try offering a tantalum set of caps separately for those who want to do it.
LC

 

[Robb]

Tantalums are best in a pll/vco circuit where stability is critical. They are also used in the audio chain as well; many 148's use them. So long as they don't get shorted, they are superior performers. If you accidentally or purposely short one; then their days are numbered and need replacement. Accidentally shorted a tantalum in a 959 pll circuit and replaced it right away.

Xit13 advised me a few years ago about C179; best to just replace it with an electrolytic and it won't have another problem. Done that to a few 858 chassis since then with good results.

 

[357]

http://www.aliexpress.com/store/group/Tantalum-capacitor/1596219_501074660.html

very good prices from this guy, electrolytic's too.

 

[Klondike Mike]

http://www.aliexpress.com/store/group/Tantalum-capacitor/1596219_501074660.html...very good prices from this guy, electrolytic's too.

Those are good price's ... but they are unbranded from China. Nuff' said. I'm not going to gamble with my reputation or radio's with unbranded Chinese products. History has already given us the answer on this. I'll stick with the tier 1 brand names that we can get here in North America. Very tempting for the gamblers though ...

 

[357]

He deals in AVX and if you see his feedback is second to none.
I have a shipment of his caps in both styles coming and I purchased a tester to double check them.
This is a good seller.

 

[TM86]

Xit13 advised me a few years ago about C179; best to just replace it with an electrolytic and it won't have another problem. Done that to a few 858 chassis since then with good results.

I'm going to second this recommendation for swapping out C179.

I have a 139xlr that I had to replace that cap in after the original tantalum exploded. When it blew, it left shrapnel marks on the inside top cover.

So, for safety's sake, replace C179 in the 858 chassis!

 

[Wulff777]

I'm going to second this recommendation for swapping out C179.

I have a 139xlr that I had to replace that cap in after the original tantalum exploded. When it blew, it left shrapnel marks on the inside top cover.

So, for safety's sake, replace C179 in the 858 chassis!

I replaced C179 with a 'standard' electrolytic cap.when I first started re-capping it.
Thanks everyone for the help.
I should start a new conversation for this question but just thought I would throw it out: Question: I no longer have my equipment to align and tune-up radios, I just have stuff like RF meters, VOHM meters, etc. can you fellers recommend a good place I can ship my radios to for alignment?
There was several places in and around Phoenix (I live in Mesa, AZ) quite a few years back but .they are pretty much gone now so I would rather ship it to someone that knew what they were doing.
Anyone on WWDX that does it?
Thanks again,
Phil

 

[357]

Those are good price's ... but they are unbranded from China. Nuff' said. I'm not going to gamble with my reputation or radio's with unbranded Chinese products. History has already given us the answer on this. I'll stick with the tier 1 brand names that we can get here in North America. Very tempting for the gamblers though ...

I got the caps and they all checked out except the 4700uf 25V nichicons.
Seller refunded me and pulled them off his store.
http://www.badcaps.net/forum/showthread.php?p=630962&posted=1#post630962

I've been testing each cap and cherry-picking the lowest ESR.