I guess I'll have to send you some more BLACK FLAG, Oops no I mean Old Spice.
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Don't buy this POS from this guy on eBay
- Thread starter Tallman
- Start date
That's good. Are you wanting to build one of these? It will need some bandpass filtering or else it's just a glorified cb amp. The ones I've been around will work 160 thru 10m with no band switch. It really needs to be filtered.
Baruch (4Z4RB) has acquired a bad rep amongst the ham QRO and contest crowd.
Poor build quality, substituting cheap capacitors in circuits with high RF current are just the beginning.
Not sure how he avoids Ebay penalties, but as the back glass on a pinball machine says "For entertainment purposes only".
73
Poor build quality, substituting cheap capacitors in circuits with high RF current are just the beginning.
Not sure how he avoids Ebay penalties, but as the back glass on a pinball machine says "For entertainment purposes only".
73
If you ever experiment with these types of transistors, there are 3 things to pay close attention to.
1) Do not skimp on the copper heat spreader. It is required because there is no other way to sink over 1kw of heat dissipation through a single package device without it. The best aluminum heatsink still needs copper otherwise the surface area of the transistor alone, is too small for proper heat transfer.
2) Do not over bias the transistor. Apply just enough bias to produce a clean signal. Pass it by a few hundred millivolts and you could easily pop the gate. For that reason, regulation is critical.
3) Do not overdrive them. Some of these transistor are capable of operating at 23db gain! One watt can produce full output in many cases. Do not think the typical radio can be turned down to safely meet this requirement. The simple 3 resistor, 50 ohm attenuator is usually required to insure peaks do not over drive the input.
1) Do not skimp on the copper heat spreader. It is required because there is no other way to sink over 1kw of heat dissipation through a single package device without it. The best aluminum heatsink still needs copper otherwise the surface area of the transistor alone, is too small for proper heat transfer.
2) Do not over bias the transistor. Apply just enough bias to produce a clean signal. Pass it by a few hundred millivolts and you could easily pop the gate. For that reason, regulation is critical.
3) Do not overdrive them. Some of these transistor are capable of operating at 23db gain! One watt can produce full output in many cases. Do not think the typical radio can be turned down to safely meet this requirement. The simple 3 resistor, 50 ohm attenuator is usually required to insure peaks do not over drive the input.
Thanks for that information. That is what I was looking for.
I have not seen you around much thanks for answering.
I have not seen you around much thanks for answering.
