Re: RD15HVF1 x RD06HVF1 (not the IRF510)
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“I think that RD06HVF1 have warmed more on 7mhz because its is not in optimum transistor performance range.”
Optimum performance range? The RDxx series transistors are true RF transistors and should perform perfectly from DC to UHF…, in fact much better than the IRF510 which were designed as motor and power supply switches. Nothing wrong with the IRF devices but the RDxx series will have better RF characteristics like lower capacitance, higher frequency response, and a better IO mapping (linearity).
I have not investigated my PA kit yet (probably because I have one of my own design working). While Hans is a pretty good engineer and designed this kit to work for most conditions… my guess would be that T1, C1, C2, C3, C6 are not optimal for the RDxx device over the entire 1-50 MHz range. In fact, I would be very surprised if they were. My back of the envelope calculations say that the capacitors should all be 0.01 and T1 needs 3 fewer turns than at 7 MHz… but those are only my estimates.
Make sure you built T1 correctly!!! From your output results, I ‘d say that is a good place to check.
Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ
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From: QRPLabs@groups.io [mailto:QRPLabs@groups.io] On Behalf Of Roney Monte
I'm testing the PA 5w Kit with the following scenarios, using just a monoband U3S, each time with a specific LPF and antenna tuned for low SWR. (The transistor normal limit is 6 watts)
I have a receiver/workstation (SDR) 2 km away, with remote access in order to watch the spectrum of each test.
50 mhz -> got only 0.2w*, but very strong signal, no propagation here (not warming)
28 mhz -> got 1.5, signal being listened in world JTs/WSPR (medium warming)
24 mhz -> got 4w, bad propagation (not warming)
21 mhz -> got 2.5w, signal being listened in world JTs/WSPR (medium warming)
7 mhz -> got 2w, signal being listened in world JTs/WSPR (warming so much)
* (Maybe my MFJ870 is not working well in 50 mhz ?)
I think that RD06HVF1 have warmed more on 7mhz because its is not in optimum transistor performance range.
On 10M/15M/40M I have been listened for more than 10.000 km.
I'm continuing with my tests. After all band tested, I will post the detailed results.
73 de PY1ZB
On Mon, Feb 20, 2017 at 10:50 AM, <ajp166@...> wrote: