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kit quality

 

are there any kits that come with decent caps installed?,mine keep frying,chinese kits tho.
 

If you're having problems with the same caps each time it's possible that the voltage/current at a certain frequency band on your particular antenna is exceeding the spec for that capacitor - you might need something a bit beefier than the design. Not sure about yours since all kits are different, most of the ones I have seen are often less than 500V, and in a manual ATU several kV would be the norm. I built mine from a PBA and used 1000V silvered mica capacitors because I had them to hand, it might be worth trying replacing the caps rather than buying another kit

It is a "home-brew" design, a degree of experimentation is sometimes necessary
 

I replaced the original caps in my ATU-100 with components in this family:



Yeah, price + shipping may add up, but in the long run, it's cheaper than repeated damage and repair.

Al, K2ZN

On Thu, Nov 30, 2023, 05:01 Alec Wood <alec@...> wrote:
If you're having problems with the same caps each time it's possible that the voltage/current at a certain frequency band on your particular antenna is exceeding the spec for that capacitor - you might need something a bit beefier than the design. Not sure about yours since all kits are different, most of the ones I have seen are often less than 500V, and in a manual ATU several kV would be the norm. I built mine from a PBA and used 1000V silvered mica capacitors because I had them to hand, it might be worth trying replacing the caps rather than buying another kit

It is a "home-brew" design, a degree of experimentation is sometimes necessary

 

As a rule of thumb I derate my tuners by 50 percent. For example, I use my ATU100 with a Yaesu FT-857 for portable operation running at 50 watts.

Mike N2MS

On 11/30/2023 10:44 AM EST Al Scanandoah <k2znqrp@...> wrote:


I replaced the original caps in my ATU-100 with components in this family:



Yeah, price + shipping may add up, but in the long run, it's cheaper than repeated damage and repair.

Al, K2ZN
 

That's right! I went overboard on "project overkill" and used 1000v silver mica or Vishay VJHiFreq RF caps in 1111 SMT format. In retrospect, 500v RF caps would have been good enough.



73 de va3rr

On Thu, Nov 30, 2023 at 10:44 AM, Al Scanandoah wrote:

Yeah, price + shipping may add up, but in the long run, it's cheaper than
repeated damage and repair.
 

Here.
 

jabdog on ebay blocked me,brought some 1% caps from him that were 15% over spec so gave them poor neg feedback so they blocked me! wankers!.
 

Whoa, did not know that is possible to block somebody on eBay. One time I have leaved bad feedback and got money back with apologies .

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