KA5PIU
11-18-2010, 11:48 PM
Hello.
I have been talking to an older ham who has decided to try and get on HF.
He does not know code and his hearing is bad, he frequently has trouble with his hearing aids feeding back, I have to point out that one is squealing.
He has trouble navigating the menu on a modern FM radio, not that this is something unusual, I program radios for dozens of hams every year.
But I am of the opinion that he will not make a good phone operator on HF, at least not as it is at present.
If he were to remove his hearing aids he would need headphones that can do 130+ decibels.
I will supply a device that can provide over 130 decibels only at the advice of a health care provider, not that this is hard it is just something I am careful about.
So what is the next step?
And, if you want to increase the volume of a pair of headphones you need only think of how most headphone feeds work.
Most are nothing more than a jack that is fed by a pair of resistors off the speaker line.
Normally something in the order of 700 ohms is the value of the resistor.
A value of around 100 ohms will produce a massive increase in volume.
The best cheap amplifiers for this task are something that is used in a cheap pair of computer speakers.
I buy the little USB powered speakers with a regular audio plug.
You can keep the original speaker enclosure and simply change the value of the resistor or mount the amp inside a small box.
the 5 volt DC needed can be provided by a USB port or an old cell phone charger with the correct ratings.
Plugging this into a standard computer headphone jack will provide the headphones with a massive increase in volume, and the danger that someone may damage their hearing.
I have been talking to an older ham who has decided to try and get on HF.
He does not know code and his hearing is bad, he frequently has trouble with his hearing aids feeding back, I have to point out that one is squealing.
He has trouble navigating the menu on a modern FM radio, not that this is something unusual, I program radios for dozens of hams every year.
But I am of the opinion that he will not make a good phone operator on HF, at least not as it is at present.
If he were to remove his hearing aids he would need headphones that can do 130+ decibels.
I will supply a device that can provide over 130 decibels only at the advice of a health care provider, not that this is hard it is just something I am careful about.
So what is the next step?
And, if you want to increase the volume of a pair of headphones you need only think of how most headphone feeds work.
Most are nothing more than a jack that is fed by a pair of resistors off the speaker line.
Normally something in the order of 700 ohms is the value of the resistor.
A value of around 100 ohms will produce a massive increase in volume.
The best cheap amplifiers for this task are something that is used in a cheap pair of computer speakers.
I buy the little USB powered speakers with a regular audio plug.
You can keep the original speaker enclosure and simply change the value of the resistor or mount the amp inside a small box.
the 5 volt DC needed can be provided by a USB port or an old cell phone charger with the correct ratings.
Plugging this into a standard computer headphone jack will provide the headphones with a massive increase in volume, and the danger that someone may damage their hearing.