Mystery RF amplifier

Рет қаралды 1,658

6 ай бұрын

Пікірлер: 30

@arenaengineering8070 6 ай бұрын

In my opinion, this low noise amplifier worked to compensate long coaxial line from antenna to receiver. Working in A class.

@ptronix 6 ай бұрын

It's certainly very linear and I'm sure it's a low noise amp, hell of a lot of gain though!

@gerriegoeree9153 6 ай бұрын

It is used for Analog FM ATV (amateur television) ....Antenna to the input, output to an old analog Sattelite reveiver. These receivers normally connect to an LNB which converts down + amplify from 10GHz to the intermediate frequency of 750 - 2100 MHz. Analog Amateur Television is normally done around 1250MHz, therefore a sattelite receiver could directly be used for FM modulated ATV. Been there, done it....(PA3EXV)

@gerl9869 6 ай бұрын

Published in 'Elektuur' Magazine, june 1996, is online download.

@danishnative9555 6 ай бұрын

I used, a discarded Uniden Sat receiver with the 1248mhz down-converter feeding the wide-band 70mhz IF port. Video quality was great.

@microwave-vh2uc 5 ай бұрын

Its a rf amplifier for 1.2ghz and its made to amplify an antenna signal and feed it into a satellite receiver. Satellite receivers need a lot of gain so that's why it has a gasfet followed by a filter and then 2 mmic stages. Probably about 40db gain al up which is what a satellite receiver needs as its designed to be used with a LNB (low noise block converter) These were used to receive FM amateur Television between 1240mhz and 1300 mhz 1.3Ghz This is very 90s tech. I built many of these.

@ptronix 5 ай бұрын

Thanks I know all that now, as a kind person sent me the original magazine article. The one I tested had a peak gain of 37 db

@dwalshaw 6 ай бұрын

It looks to be a low noise receive preamp with DC injected into the coax, it also looks like a Mini Kits kit. I have one very similiar

@ptronix 6 ай бұрын

I'm sure it is, hell of a lot of gain though

@danishnative9555 6 ай бұрын

Avantek and Mini-Circuits 50 ohm gain blocks were an essential for roll your own RF experimenters back in the day. They still live on, and offer many reasonably priced filters and RF devices. Happy New Year Nick 73' and kudos to the person who constructed that amplifier.

@ptronix 6 ай бұрын

Happy new year to you Paul. I forgot to mention hp also made them. The one marked Ao6 is by hp and I have a few of those. I've the urge now to tweak the capacitors in the band pass filter.

@danishnative9555 6 ай бұрын

@@ptronix HP had some fine low noise semi's, though I don't know if they had their own wafer fab or if some 3rd party made them. The A06 might be very similar to the Mini MAR-6 which has a lot of gain, and will easily blow if abused. Afterthought: Maybe for 1248mhz FM ATV or 1296. Gasfets better and loop Yagi's preferred.

@ptronix 6 ай бұрын

@@danishnative9555 hi Paul, the A06 is actually an MSA-0686 by hp. Its maximum gain is 16.5 db but drops a bit at the frequency in this amplifier. I used them to replace some crap Philips devices that were used in a signal generator. There were 7 of them and one by one they all failed. I still think the input device is a gasfet for low noise. I gave up on 23 cm years ago, too many hills around me, the furthest contact I managed was only 50 miles.The IC 9700 is a lovely radio for 2m but wish it had another band on it rather than 23 cm!

@danishnative9555 6 ай бұрын

@@ptronix Interesting because the Mini MAR-6 has "06" printed on it as shown by the data sheet, but the two devices seem dis-similar otherwise.

@ptronix 6 ай бұрын

@@danishnative9555 hi Paul, mystery has been solved. Email from a Dutch guy. This was a project in a Dutch electronic magazine, its a low noise amateur TV preamp. Sent me a link to download the pdf. Trouble is it's in Dutch! But gives me more info. First device is a gasfet as I suspected. MGF1302 followed by two MSA-0686 by hp. Or MAR 6 by mini circuits. May do a follow up video as it's been very popular so far.

@ruhnet 6 ай бұрын

Hey, great video! You could find out the appropriate RF power input range by sweeping the input amplitude with a two tone generator and watching the IMD products. (I made a video about this for identifying unknown amplifiers). Happy new year!

@ptronix 6 ай бұрын

Happy new year to you. A two tone generator sounds a bit complicated but I get the point. Think I will test its maximum power output before compression though

@mikecass8306 6 ай бұрын

Thanks Nick, happy new year 😀

@ptronix 6 ай бұрын

Happy new year to you Mike, thanks for watching

@matambale 6 ай бұрын

That's quite a performer. enjoyed the investigation. Really tempted to suggest it might be usable as a TX amp, with that much gain. Would need beefy heat-sinking though, yes?

@ptronix 6 ай бұрын

I'm kinda thinking the same Joe, transmit amp. I should have measured the power output, but it can't be that high with no heatsinks on the gain blocks. I'm also thinking the first device on the input may be a gaas fet after all

@alankendal5857 6 ай бұрын

Could be for fast scan TV on 1249MHz or 1255MHz.

@ptronix 6 ай бұрын

I'm sure it's a low noise preamp but a hell of a high gain on it!

@TorbenRune 6 ай бұрын

It is a GPS L2 (1227.60 MHz) amplifier?

@ptronix 6 ай бұрын

I'm sure it's a low noise amplifier for the 23 cm amateur band

@TorbenRune 6 ай бұрын

@@ptronix It could be, but the relative sharp frequency response and the 30 dB amplification is often what we see on GPS amplifiers. BTW Is the power supply to the output BNC passed through to the input BNC? (If so, this might indicate that it is an in-line amp to compansate wire loss).

@ptronix 6 ай бұрын

@@TorbenRune it's not got a particularly sharp frequency response, it perfectly covers the the 23 cm amateur band, yes it's powered up the coax and no there is no power to the input bnc

@TorbenRune 6 ай бұрын

@@ptronix ok, then it is probably not a GPS amp.

@frspascal 6 ай бұрын

I would say a little rf amplifier on 1300 mhz in on the left and out on the right... Filter seems to be around 1255 to 1300 mhz..