thanks for the good info, it's a keeper! Leonard G. Caillouet wrote: > > Just a few notes on these transistors and the results of some experimenting. > I had a KV27ts32 and a KV32s25 in the shop with the classic HOT shorted and > Q601,602 shorted. I had some 2SC4834M in stock and ordered some plain > 2SC4834 from Tritronics and some 2SC4834P from Acme Enterprises (Orlando). > I tried each type in both sets and found that the higher rank (letter) > transistors ran progressively cooler. I matched the transistors from > batches of 10 by forward bias voltage on the junctions then in circuit for > nearest to 50% duty cylce. I have found that swapping pairs or swapping the > caps on Q601,602 can often improve the ratio to closer to 50%. > > Interestingly, the higher gain transistors ran cooler by 10-20 degrees, > depending on the set, but the overall current drawn by the set was virtually > the same(~60-70 mA with & without a signal) > > Summing up, it appears that the higher rank transistors are the better > choice. Acme has them at a great price(10 for $15.95) and has free shipping > for the time being on orders over $25. They are a new operation but Glen, > the main contact there was a manager for MCM at one time and seems > veryinterested in winning over the business of shops like us. So far they > seem to be good to work with. > > BTW, the KV32S25 was a bit atypical in that the HOT failure was due to a bad > FBT. The price was pretty steep and the customer did not want to fix it, so > I gambled and tried an aftermarket transformer from HR. It seems fine so > far and at the lower price the customer went for the fix. We'll see if it > holds up. I don't like subbing flybacks but these have had a good rep. > > Leonard G. Caillouet > Electronics World > Gainesville, FL > 352-332-5608 > 352-332-5668 (fax) > > ***************************************************************************** > Classifieds! Buy or Sell! > http://sell.tech-assist.org > The Tech Address Book: > http://www.tech-assist.org/secure/tip/contact.htm > Add a Repair Tip Here, or Change/Remove your Email Address: > http://www.tech-assist.org/secure/tip/main.htm > Lost Password: > http://www.tech-assist.org and select "Lost your Login Info?". > Email Archives: > //www.freelists.org/archives/techassist/ ***************************************************************************** Classifieds! Buy or Sell! http://sell.tech-assist.org The Tech Address Book: http://www.tech-assist.org/secure/tip/contact.htm Add a Repair Tip Here, or Change/Remove your Email Address: http://www.tech-assist.org/secure/tip/main.htm Lost Password: http://www.tech-assist.org and select "Lost your Login Info?". Email Archives: //www.freelists.org/archives/techassist/