Wow, thanks for the heads up TO & shocked at the lack of protection & BPF circuitry. Agree, to bring it up to spec you may as well buy an XPA or similar better amp. There are a stack of these simplistic RF amp designs all over the net but the bleed back is worrysome as it can easily cook the RF finals in your rig. I've built similar amps in my college days & is something every ham should try at least once. When I've seen you test other amps their power output was fairly consistent. I feel the toroid transformer construction is only scratching the surface of what's wrong with this amp. Can only dare imagine how Mike (Mikes Radio Repair) & Peter (TRX lab) would react to this amp!
No low pass filters on the output of the AMP, and it is likely the harmonics are not suppressed the required 43dB with respect to the fundamental required by the FCC. So it is probably not legal to have on the air, but really nice that it destroys itself keep you from violating the rules.
I didn’t waste on that’n ‘cause I knew it was unfiltered. If it had filtering, bet it would have done better. Worse yet: there are a couple versions ‘out there.’
Exact same thing happened to mine. This cannot handle any antenna greater than 1:1.5 SWR. One of the 530 was blown. Replaced it and it came back to life. It works, but it's fragile. Sold it to a friend who knows how to handle it with care. Oh, another thing, when the 530N blows out, the dc power plug is shorted. Be careful.
Amps, weather for audio or rf, are rarely rated at rms, they are more interesting if they are wearing an emblem of peak. It can do peak safely, for a few seconds. That 50watt amplifier, with ssb or cw, should be fed the specific amount of power to be just under that, especially with cw, which is short carriers. SSB could peak right on 50watts, or a tad more, but then you are stressing the recycled solder, and whatever they picked out for components. It needs a rig set to a specific setting of happy place and never exceeded, or just there to bypass straight to antenna. Once you have a few of them, you can start combinding them. A ssb signal @ 3 watts peak, driving 2 of those, then those driving 6 of those, of course after you develop a harmonic elimination circuit to keep it clean and focused on the bands of choice. Then you discover the little white transistors, with much higher gain and peaks, but that is kinda trendy.
@@temporarilyoffline What he said was , you over drove it to failure . never look to see advertised watts in RMS/AVG . 50w PEP not RMS . Its a gateway to popping skylab pills if your keen. near as I can finger from Mr. Late offered up.
The Micro PA50 works much better for me. It looks like it does not have any protection in the Amp. Based on final failures in the SbitX, the finals failing will cause a dead short when they go.
That amp has a lot of issues. There is no protection circuits. That is one of the things the Micro PA50 has that this amp doesn't. Lots of protection built into the Amp.
I knew that thing had a pair of IRF530s before you took the lid off. There are several kits that use those switching Mosfets. They put out a lot of power on the low bands but they short out easy as they aren’t designed for RF amplification.
Hams repurposing one thing to do another thing... No problem there, it's what we do. The micro PA50 uses the same FETs, but is a better design. I'd still like to see more protections built in though
No problem! The new hot cheap amp is: ebay.us/RxZ9x9 I haven't gotten one for testing yet, but others have said its a good start for its price. I need to get one to test out.
This low quality amp is only meant to be used (per its spec) from 3 to 21 MHz. I notice that you began your test on 160 meters (out of manufacturer's spec) and then ran through the "approved" 80-15 meter bands but then did a bit of transmitting on 12 and 10 meters (again, out of spec), and finally returned to out-of-spec 160 meters where you blew up the amp. I'm not saying the amp wouldn't have blown up anyway given that it's made of reused solder and dog food, but I am saying that you may have sped up the problem by using it in ways the manufacturer never intended. Thoughts?
Good points! I don't know where I got the idea that it worked on those bands. I'd expect it just wouldn't be efficient. The IRF530s aren't even meant for this application anyway.
@@temporarilyoffline Pushing the envelope, by instinct. I bet it would be sweet on 40, 20 metric bands. Would be cool if everything was repairable via firmware update. This may have provided a break.
I had a person hand one to me blown up in the same manner as that one that failed for you and found the MOSFET shorted-the soldering is pretty bad and I noticed around one of the BNC connectors a spot on the board where it looked like it got hot and discolored the board-which also may be the soldering job on it from the factory-they have always said-if it looks too good to be true-like 50 watts for about 50 to 75 dollars it probably is too good to be true
Got damn. I see a lot of recycled solder. I just took apart a clone of a btech (so a clone of an anytone). The only actual part problem was the roach issue. I'll update you if you want since I just found the gnar inside. But if it costs me more than the unit to clean it and get it running, then I think I quit.😆 I kid, but you know what I mean.
@@temporarilyoffline True, but it can't _"legally"_ be sold commercially ... (Yes, there's always AliExpress ...) I remember the days when commercial linear amplifiers couldn't cover 10/12 meters unless you identified yourself as a ham and got a workaround, just like the _MARS/CAP "out of band"_ mods.
I bought an OGS-50W before I saw the videos that dislike it. I figured they abused the amp, thus their issues. To be safe I used a 40 meter resonate antenna. I also used my bitx-40, but since at 13.8 volts with adequate amps it puts out around 7 watts I decided to try running the bitx-40 at 9 volts with at most 2 amps. This brought my rigs power down to 0.8 watts on my crappy meter, but the combination of an input of 0.8 watts and the OGS-50worked great. I'd say my meter suggested 28 watts. The only issue is the recieve to transmit relay has a delay of about 200 miliseconds. I spoof this by tapping the mic before starting my audio. On digital modes this could be an issue but I really bought it for giving more kick to my Qrp kit SSB rigs.
Where are the low pass filters for each band?! This amp shouldn't be allowed on sale without the LPF as it will fail all the necessary test/approvals. 73 Bruce G4ABX
No filters! Mica insulators double-stacked - doesn't make sense why they would do that; decreases thermal conductivity... And that RF sense circuit. Hot garbage!
I thought the insulators might appear that way on camera, it was one per FET, not two stacked. But as you know, you can't go back and re-shoot something later. The whole thing was hot garbage though!
