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anybody used BD139?

 

has anyone used bd139 as power amplifier? how does it perform at 14 mhz and beyond?
Dimitar Pavlov
 

Hi,

I'm use it in last 4 cw homebrew transceivers. 1 transistor gives 1/2 Watts in output.
It works well to 10MHz, Upwards its power drops to 1/2 (but this may also be due to poor tuning between the transceiver and the antenna). They are Burns quickly in bad SWR conditions (over ~ 1:3). It is good to have a zener diode at the exit to protect transistor.

73!
On Monday, June 26, 2017 11:49 AM, Ashhar Farhan <farhanbox@...> wrote:


has anyone used bd139 as power amplifier? how does it perform at 14 mhz and beyond?
 

Hello Farhan

I use the BD135, BD137 and BD139 in many experiments, all these are OK for frequencies up to 30MHz, but I use from Phillips or Motorola all others dont have the same perform in frequencies in frequencies above 20MHz.? ...Recently I? bought BD139 from China but they do not have the same features as the BD139 (they have a PH mark) of those brands.
Some americans hams are using the 2SC5706 ...I bought they also, but I dont made experiments with.
For 14MHz? the 2SC1173 or the BD135/ 137/139 are OK.

73 from py2ohh miguel
 

It's effectively used in VK3YE's "Beach 40" (two of 'em, driven by a 2N2222!).

I've used the BD139 with it's complement BD140 in an audio amplifier. Works a treat...

?

Mike Y, KM5Z

Dallas, Texas USA
 

thanks everybody. wes' updated qrp transmitter has put ont 6 watts on 7 mhz from the BD139. i have a couple that i will evaluate for the distortion.

- f

On 26 Jun 2017 3:47 p.m., "Miguel Angelo Bartie via Groups.Io" <py2ohh=[email protected]> wrote:
Hello Farhan

I use the BD135, BD137 and BD139 in many experiments, all these are OK for frequencies up to 30MHz, but I use from Phillips or Motorola all others dont have the same perform in frequencies in frequencies above 20MHz.? ...Recently I? bought BD139 from China but they do not have the same features as the BD139 (they have a PH mark) of those brands.
Some americans hams are using the 2SC5706 ...I bought they also, but I dont made experiments with.
For 14MHz? the 2SC1173 or the BD135/ 137/139 are OK.

73 from py2ohh miguel

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