Two Scales QRP RF Wattmeter And Dummy Load - 1W / 10W or 2W / 20W
ฝัง
- เผยแพร่เมื่อ 7 ก.พ. 2025
- Get $5 of NEW USER FREE CREDIT using PCBWay. Full feature custom PCB prototype services, PCB assembly, SMD stencils and CNC / 3D Printing: pcbway.com/g/g...
Some of the links above may be affiliate links and I earn a small commission at no expense to you.
Simple Wattmeter and dummy load that allows you to measure the RF output power. Designed for QRP with 1W / 10W or or 2W / 20W scales. Is a simple design based on another simple QRP wattmeter from Peter - @vk3ye .
If you enjoy the videos be sure to subscribe !
73, YO6DXE
PCB BOARD:
www.pcbway.com...
VIEW ALL PCB PROJECTS:
www.pcbway.com...
BLOG POST:
dxexplorer.com...
DX EXPLORER:
A channel with amateur radio related videos on: schematics, kit building, homebrewing and more.
I am passionate about amateur radio since childhood. I got back into the hobby in 2016, while living aboard my sailboat. I received my license in 2022. I like QRP mostly, experimenting with all modes. But I am old school, so I prefer SSB or CW.
#amateurradio #hamradio #electronics #pcbway
May be you are getting close results , but this is not the right formula P= (Up*0.707+Udiode_drop)squared /50
U av=Upeak *0.707 or in some sources is Uav= Up*1/1.41
Thank you so much. Ohh I will make you laugh. Every time I update the formula someone tells me is the wrong one hahaha. So I will write it down for me to know it and learn from it. What I did at the end is that I calibrated the meter using an already calibrated power meter so I no longer have to calculate things as honestly I no longer know what is the right formula 😅😅😅. Thank you so much one more time. 73, YO6DXE
Looking forward to this project! 73 !
Soon in a box as well I hope. 73 and a fantastic weekend.
@@dxexplorer You as well!
Привет из России! Я всегда скупал на блошиных рынках такие стрелочные приборы, у нас в промышленном городе раньше их были сотни на заводах и в гаражах у людей. Из них хорошо ещё делать S-метры для приёмников и КСВ-метры для передатчиков.
Привет из Румынии. О да, у меня тоже многое осталось от отца, когда я был моложе. Тоже взяли с завода... но тогда они мне были не нужны и я их выбросила... теперь они хорошие 😅😅. Они идеально подходят для ваттметров и S-метров или КСВ. Теперь... надо их купить 😅😅. Хороших выходных и 73, YO6DXE.
hi. Great project. But i believe the formula is P = ((V + Vdiode)^2 ) / 100
source : AA5TB's qrp power meter, solving for the Vpeak
P ( W ) = ( V + 0.25 ) / 50, where 0.25 is the voltage drop of the diode for peak to peak power... your formula for RMS indeed. You get to peak what the meter shows you )).
I believe you are correct. AC would be V^2 / R (ohms law), with V as the RMS value. This device is peak reading; to convert peak to RMS you divide by sqrt(2). Once you square V/sqrt(2) you get V^2 / 2, then divide by R, so you end up with V(peak)^2 / 2R (remember to add the diode drop to V).
Sorry for the late reply... I had a long day yesterday. Yes... the formula to use depends on the result you want to get. In my case I am interested in the peak to peak power. I found it easier for younger kids that usually don't like calculating that you can borrow a proper power meter, or use a transceiver that has a power meter incorporated and use that to calibrate the wattmeter to your needs. It seems to be more accurate than I was expecting to be honest... even though I was not looking into very accurate readings when I built it. I just wanted to have an idea of where about I am with the power output and if I do have RF going out from whatever I was testing. Is a really simple and basic tool but it seems to be a great thing to have around. I think I will modify it to the 1W or 2W / 20W version though so I can also test equipment that has a little over 10W. With the diode I used it seems to do just fine on VHF and UHF as well and I was not expecting that either. Love it 😁. 73, YO6DXE and wish you all a fantastic weekend.
Nu-mi vine sa cred... chiar acum cautam cum sa masor putere RF in cel mai simplu mod posibi. M-am dat batut, si ce apare la recomandari? Video-ul ăsta :)))
🤣🤣🤣 am simtit eu ceva si am zis sa pun ce trebuie hahaha. 73 si zi faina de tot. Ma duc sa mai dorm o ora daca apuc 🤣
@@dxexplorer Multumesc, zi faina si tie. Totusi am o intrebare, de unde e acel ampermetru? Eu am gasit pe emag ceva similar care merge pana intr-un amper dar nu e chiar acelasi (l-as folosi pe acelasi ca sa se potriveasca hartia)
@bobi_lopataru Tot de pe Emag am luat si eu ))). Stai sa caut si it las link imediat. Eu am folosit de 500mW doar ca am scos cam tot ce avea in el si a ramas doar ce se vede in video ))
@bobi_lopataru Ba nu de pe Emag am luat ci de aici: componenteonline.ro/ampermetru-analogic-de-panou-500ma-dc-ampermetru-de-panou-ampermetru-cu-ac-111445?product_id=4224
Este si pe Emag tot de la doamna, doar ca am preferat sa iau din magazinul lor in loc de Emag. 😁
@@dxexplorer Multumesc, uite ca am mai aflat de un site cu componente electronice
If you have double triode you can make audio amplifier with mosfet in schematic it works from 24v
also if you can write me wich tipe of tubes you have i can send you easy schematics on low voltage
That sounds AMAZING 😁😁 Thank you so much. I will write a blog article this weekend and put a list there of all the tubes I have so far... and I will send you the link. I need to catch up with you on the email as well. Maybe later on today 😁. 73 and have a fantastic Friday.
@@dxexplorer thanks. Also I will show you my regenerative receiver on tubes wich works 80 and 40 meters AM, CW and SSB modes😁.
73! 4L1LAT
@inventor2540 Ohh yes please 😁