I guess I'm doing things right, I have a Yaesu FT991A and a Ameritron ALS-600 with a MFJ-989D (legal limit) manual tuner on the outside, I put the amp on standby and tune at 100 watts, I lower the drive to 45 watts and engage the amp, the tuning is spot on. Thanks for confirming my setup is correct :) 73 de AI5DD
Of course, if you have a non-resonant antenna, a tuner is going to be necessary especially with solid state amps which usually will go into fault mode if the SWR is above 2:1.
How do I resolve high swr between the amplifier and the radio? I heard I can solder some 5W carbon or metal film resistors around 100 ohms between ground and the driven pin (coming from the radio coax into the amplifier and going to where it switches across to on the input side of the main relay that switches the signal into the amplifier stage when you key. I guess it bleeds off some of the reflected signal before it gets to the radio. Perhaps i would be better off winding some type of choke on the input side?
Also when bypassing an amp you have to make sure what the bypass wattage is for the amp so its bypass rating doesn't effect the reading on the final tuning meter, For example if the amps bypass rating is a hundred watts when the amp is switched off you don't want to be running more than a hundred watts from the radio/exciter through the amp to the tuner/meter/antenna.. this will result in damage to the amp and a wrong final meter reading.
Hi Dave, older video I see, so HF rig, 10 metre amp , then external ATU ( correctly rated) to antenna ( in that order! SWR meter built into ic7000 . regards Andy (UK FULL licence)
Some amps have input tuning and grid current metering and if you can't get a working match, somethings burned up. While solid state amps need a tuner for random antennas, tube amps have a much wider matching range.
If you have high SWR between your radio and Amp , make a tuned input for the amp and tune that for 50ohm .. make surenit can handle the output of the radio.. tounwill more than likely hahe to make one for every band depending on the type of amp .. Many older tube amps and even some newer one have tuned inputs.. Make sure to tune these inputs with a 50ohm dummy load behind the amp .. so tjat they won't change as you tune your final antenna tuner to 50 ohms..
So if I have a 50ohm amplifier and I have a perfectly matched good swr on my antenna and going to stay in one band in the frequencies I have good swr, Do I need a tuner at all ????
I ordered an amp to solve my barefoot CQ blues. The bad news is the manufacture is waiting on parts to be delivered to their plant in California - it might take an Act of Congress to get them there.
20 or 30 years ago. You make me feel old. Been Ham since 65. Boy, time goes by so fast. Always enjoy your UA-cams.
CONGRATULATIONS on finally reaching 100K SUBSCIRBERS!!! Well-deserved Dave :) 73 KJ6ER, Silicon Valley
I guess I'm doing things right, I have a Yaesu FT991A and a Ameritron ALS-600 with a MFJ-989D (legal limit) manual tuner on the outside, I put the amp on standby and tune at 100 watts, I lower the drive to 45 watts and engage the amp, the tuning is spot on. Thanks for confirming my setup is correct :) 73 de AI5DD
Since 1984 mine is set up , radio, SWR meter, Amp. Never had a problem.
My friend and I were just talking about this. Some amps have tuning pots on the rear panel to make adjustments.
Of course, if you have a non-resonant antenna, a tuner is going to be necessary especially with solid state amps which usually will go into fault mode if the SWR is above 2:1.
How do I resolve high swr between the amplifier and the radio? I heard I can solder some 5W carbon or metal film resistors around 100 ohms between ground and the driven pin (coming from the radio coax into the amplifier and going to where it switches across to on the input side of the main relay that switches the signal into the amplifier stage when you key. I guess it bleeds off some of the reflected signal before it gets to the radio. Perhaps i would be better off winding some type of choke on the input side?
Is this discussion for a specific type of antenna? Or would this work with a random length antenna, G5RV, Inverted V? I'm new to HF
Also when bypassing an amp you have to make sure what the bypass wattage is for the amp so its bypass rating doesn't effect the reading on the final tuning meter,
For example if the amps bypass rating is a hundred watts when the amp is switched off you don't want to be running more than a hundred watts from the radio/exciter through the amp to the tuner/meter/antenna.. this will result in damage to the amp and a wrong final meter reading.
Hi Dave, older video I see, so HF rig, 10 metre amp , then external ATU ( correctly rated) to antenna ( in that order! SWR meter built into ic7000 . regards Andy (UK FULL licence)
That is correct
Some amps have input tuning and grid current metering and if you can't get a working match, somethings burned up. While solid state amps need a tuner for random antennas, tube amps have a much wider matching range.
A tuner at the antenna vertical
Was would you use or recommend KQ4CD Paul
If you have high SWR between your radio and Amp , make a tuned input for the amp and tune that for 50ohm .. make surenit can handle the output of the radio.. tounwill more than likely hahe to make one for every band depending on the type of amp ..
Many older tube amps and even some newer one have tuned inputs..
Make sure to tune these inputs with a 50ohm dummy load behind the amp .. so tjat they won't change as you tune your final antenna tuner to 50 ohms..
So if I have a 50ohm amplifier and I have a perfectly matched good swr on my antenna and going to stay in one band in the frequencies I have good swr, Do I need a tuner at all ????
100000 subs 👌 Well done.
Hi Dave is the giveaway open to VK residents as well?
Anyone notice the lamp on the cabinet behind Dave leaning over lol
Another good vid.
I ordered an amp to solve my barefoot CQ blues. The bad news is the manufacture is waiting on parts to be delivered to their plant in California - it might take an Act of Congress to get them there.
Thank you. That helps. N0QFT
👍🏻