Really liked this video, but could you explain the impedance matching using the transmission line transformers? I understand the 1/4 wavelength tlt formula (sqrt(Zo*Zin)), but how were you able to use a transmission less than 1/4 wavelength? Thank you!
The total length of coax cable for this TLT is just under 1/8 wavelength. This cause a phase shift in the standing waves in the transmission line. The phase shift is approximately 90 degrees which causes the 2 standing waves to cancel each other out. When these waves are cancelled Zo = Zl. Regards
55volts @ 20amps = 1100watts input power and 1000watts output power, that's over 90% eff. wow I'm a bit skeptical. I've seen similar designs in the range of 66 - 75% eff. I don't see this pallet listed on your website yet, I'll check back. I'm interested depending on price even if the eff. turns out to be more typical to others. Thanks for the video
I believe my current meter was reading a little low. I will have the 2 M board posted on my site next week. The price is $519 with the copper heat spreader, plus $16.95 shipping. Thanks!
Should have band pass filtering to avoid spurious emissions and interference with other services. It seems that none of these LDMOS amps designs focus on that. Too much emphasis on wattage and not on clean signals with these Ebay amps. People should be aware of this.
Dear sir I have 500watt mrf 300an vhf amp But I confuse about to bias setting Ple suggest how to set bias ,I am new in this field if you possible then ple make a video
🤣Did you catch that ? @ 6:55 We use the infamous *Flux Capacitor* - From "Back to the Future" - HA HA HA 😂🤣
i see there is an error in the calculation 20.6 x 0,70 =18.1 isn't the amount 14.42.. and where can you get a length of 12cm for 2 meters??
Ordered one, can you show the input and output waveforms on a scope?
Beautiful job!!! The BLF188XR costs only $80-100 in Russia. 73 from RA3ASA Leo!!!
Nicely done!!
Really liked this video, but could you explain the impedance matching using the transmission line transformers? I understand the 1/4 wavelength tlt formula (sqrt(Zo*Zin)), but how were you able to use a transmission less than 1/4 wavelength? Thank you!
The total length of coax cable for this TLT is just under 1/8 wavelength. This cause a phase shift in the standing waves in the transmission line. The phase shift is approximately 90 degrees which causes the 2 standing waves to cancel each other out. When these waves are cancelled Zo = Zl. Regards
Is the LDMOS soldered to copper base? Or just bolted?
Hi, can you shar the page you show on the video. It is hard to read because too mutch move .... :) Please sent a link to download this doc. thank you.
Hello, good day, how much is the donation to have the exell?
55volts @ 20amps = 1100watts input power and 1000watts output power, that's over 90% eff. wow I'm a bit skeptical.
I've seen similar designs in the range of 66 - 75% eff.
I don't see this pallet listed on your website yet, I'll check back. I'm interested depending on price even if the eff. turns out to be more typical to others.
Thanks for the video
I believe my current meter was reading a little low. I will have the 2 M board posted on my site next week. The price is $519 with the copper heat spreader, plus $16.95 shipping. Thanks!
Actually that of the most device is a 1200 watt device and his boards are designed to be 85% efficient
What type of PCB material is this? FR4 or Rogers, PTFE etc ? I kinda assumed that ordinary FR4 was not so good at VHF
hello sir do you ship to Philippines
Should have band pass filtering to avoid spurious emissions and interference with other services. It seems that none of these LDMOS amps designs focus on that. Too much emphasis on wattage and not on clean signals with these Ebay amps. People should be aware of this.
Thank you so much!
power supply how many amps؟
What you use Thermal paste ? or solder ldmos in copper plate ?
I use a nonconductive compound with a rating of 3.3 W/mK or higher.
What is the max power of that Transistor
1400w
sir pleas can you share this excel?
Done
@@rfmanchannel6915 hello friend donate how many?' Thank you
Dear sir I have 500watt mrf 300an vhf amp
But I confuse about to bias setting
Ple suggest how to set bias ,I am new in this field
if you possible then ple make a video
Why doesn' t he buy a camera pod ? We get all shaky.
Sorry, It hard to record one handed.
I now have a tripod so you should see better quality videos!!
Feeling kinda dizzy due to all the quick camera movements. But still a nice video!
Notice he puts special circular motion on the camera to emphasize the areas he's talking about - just to keep things blurry ; )