i need help in finding a way to manually key a texas star dx1600 (sweet sixteen) amplifier. i want to key the amplifier using the amplifier relay control in the radio, i dont want to RF key the amp. i dont like the delay and micro second hot keying associated with rf sensed keying. any help would be awesome.
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how can i manualy key a texas star dx1600?
- Thread starter groundwire
- Start date
Looks like Q1 is the keying transistor. All you need to do is ground the emitter of that transistor to key the amp. Look at the trace the emitter of Q1, R1, D1, and C49 are soldered to. There may be an existing green wire that you can use if it wasn't removed for the cee bee conversion.
The remote socket will not key the amp. Just turns it on and off. Nothing happens until Q1 grounds the coil of the relay.
http://www.cbtricks.com/Amp/txstar/dx1200_dx1600/graphics/1200_1600_cwtx_inter_connection_layout.gif
Good move on manually keying the amp. RF sniffers suck.
The remote socket will not key the amp. Just turns it on and off. Nothing happens until Q1 grounds the coil of the relay.
http://www.cbtricks.com/Amp/txstar/dx1200_dx1600/graphics/1200_1600_cwtx_inter_connection_layout.gif
Good move on manually keying the amp. RF sniffers suck.
Ground the emitter of Q1 keying transistor to ground. This will manually key the amplifier.
do this with no radio/RF connected to the amp.
You do this to check bias voltage to the power transistors.
Input side of the input transformer to ground ..... (.6~.7 vdc)
do this with no radio/RF connected to the amp.
You do this to check bias voltage to the power transistors.
Input side of the input transformer to ground ..... (.6~.7 vdc)
awesome, perfect. now, should i use a keying interface to protect the radio? (like the ones from ameritron). or will direct connection to the radio be fine? im just concerned about amplifier keying voltages damaging the radio. like you would find in old tube type amplifiers.
Umm, direct connection to *what* radio?
Some of them require an interface to switch anything over 5 Volts DC.
In your case, if it says the radio's keying output is good to 14 Volts DC, you're good to go.
The specification page may have this spelled out, or you may have to dig deeper into the radio's manual for the limits of the radio's linear-key output.
They're not all created equal in this respect.
73
Some of them require an interface to switch anything over 5 Volts DC.
In your case, if it says the radio's keying output is good to 14 Volts DC, you're good to go.
The specification page may have this spelled out, or you may have to dig deeper into the radio's manual for the limits of the radio's linear-key output.
They're not all created equal in this respect.
73
Shadetree Mechanic
Delaware Base Station 808
You can use an interface but it's probably not needed. Check the manual for your radio. It should have specs for the max current it can handle. Then stick your multimeter from the emitter of the keying transistor to ground. The amp should key and you'll get a current reading.
The ameritron keying interface is mainly for old tube amps that have 120 volt relays. Since the texas star uses a 12 volt relay you should still be ok. Double check the manual for your radio make sure it will handle 12 volts and the current you measure.
The coil current of the keying relay in the drawing above is under 1/10 of an Amp. Should not be a problem for any radio that uses a relay contact to activate the external amplifier.
But there is a way to reduce the keying current. Hook your keying cable to the base of Q1 rather than the emitter. This will reduce the keying current to a few milliamps. Won't reduce the open-circuit voltage, but that won't be any more than the power-supply voltage you use to operate it.
73
But there is a way to reduce the keying current. Hook your keying cable to the base of Q1 rather than the emitter. This will reduce the keying current to a few milliamps. Won't reduce the open-circuit voltage, but that won't be any more than the power-supply voltage you use to operate it.
73
Here's what we use to add external-amplifier keying to a (cough-cough) 10-meter ham radio. None of them have this feature.
Odd.
[URL]http://www.nomadradio.com/OldNomadWebPages/KBTurbo/index.htm[/url]
We use a 5-Amp relay that will safely key even the crudest bowl box made with a 120-Volt AC keying relay.
Fits okay in some mobile radios. Not so well in others, especially mobiles that have an amplifier built into the bottom cover.
73
Odd.
[URL]http://www.nomadradio.com/OldNomadWebPages/KBTurbo/index.htm[/url]
We use a 5-Amp relay that will safely key even the crudest bowl box made with a 120-Volt AC keying relay.
Fits okay in some mobile radios. Not so well in others, especially mobiles that have an amplifier built into the bottom cover.
73