Hi
AWA group of radios use a number of those big black mica and silvered mica capacitors. What can be replaced by modern capacitors? Can Silvered mica of old be replaced by mica caps. available today? Can they all be replaced with say film capacitors?
Regards
Bobpradio

The big black Mud type capacitors can be replaced by the 630V "Red" Greencaps. There may be difficulties getting a full range of these.

I prefer the yellow axial types AVETCO have them others may? They look more original and are longer in length, which helps as they are similar to what is being removed.

The Silvered Mica of today are OK and often you can use Ceramics, but make sure they are 500V types especially on the HT. I do not like them as some seem to be "inductive" and pick up signal.
You may have to scratch for low value SM's as not many suppliers stock them

With Australian radio's SM's are fairly reliable (USA seemed to have a lot of problems with siver migration in their's?) I generally do not replace these as it is normally only the ones with high voltage on them that fail.

I have only found a few, often a dud batch in the one radio. say about six in 100 radio's repaired.

Hi
I have never heard of any AWA "Mica" capacitors (rectangular black encapsulaed or earlier open types) giving any trouble; unless of course they have been subjected to severe mechanical damage.
If it aint broke don't fix it. The Encapsulated paper (cylindrical) types are another story and often become leaky, on the other hand they can show signs of severe cracking of the pitch and still perform ok.

What tends to happen if the cracking is at the ends, they will break off and short. I have seen several do this.

I have also seen several Styroseals recently that have done the same act?

Would agree with the mud AWA SM's, only ever replaced a couple that broke.

Marc