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amp relay sticks
- Thread starter groundwire
- Start date
Sure makes it sound like a bad keying transistor. The number tells the whole story, unless someone scraped it off.
How much drive do you feed this box? If it overwhelmed the keying circuit, a new one that won't croak would be better.
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How much drive do you feed this box? If it overwhelmed the keying circuit, a new one that won't croak would be better.
73
just a 4pill driver. about a 45w carrier in and 600pep. just loafing the 32pill. the keying transistor is a tip41c
At that power level you'll need a hefty resistor between the input jack and the diodes. A drive level this large tends to wear out the contact points on the relay's receive side from the arc your drive power strikes across the gap as the receive side points draw apart with RF pumping into them.
At this kind of drive level, the relay will benefit from a direct-key hookup like ham radios use for keying a linear.
Gives the amplifier relay a head start before the RF revs up.
Testing the transistor and the diodes would reveal what has survived.
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At this kind of drive level, the relay will benefit from a direct-key hookup like ham radios use for keying a linear.
Gives the amplifier relay a head start before the RF revs up.
Testing the transistor and the diodes would reveal what has survived.
73
Something to consider/stick in the back of your mind here. Consider going direct key or PTT. I never liked those RF sniffer keying circuits especially for sideband. Going direct key would require you remove the keying circuit all together and design a small box that your Mic would plug into. Going into detail would be too long for this post but coming out of the box one wire and plug would go to your radio like usual and the other wire would go directly to the keying relay wired to the same pins that put your radio into transmit. Now when you key the mic it shorts one leg of the amp keying relay to ground. Great for sideband because as long as you squeeze the Mic, the amp relay will stay engaged. I take it one step further in my keyer box by sending 12 volts directly to relays anytime I key. Like I said, something to stick in the back of your mind. Have fun and experiment. It's what radio is all about.
ok, all the parts have been ordered to properly make the keying circuit etc. if it still acts up, im just going to go with the foot pedal keying. it will also allow me to manually key the relay to see if it works properly, which will show that the sense circuit is indeed at fault. in fact i am probably going to set up the direct key now while i wait for the parts just to see if the amp works correctly and i can test it now
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yup. im putting the spike diode across the relay coil and the capacitor and #43 ferrite ring on the high side of the relay as linear one has told me.
Also, any diode, like a 1n4007, 1n5408,:etc work but I made the switch to Schottky diodes, a bit faster. Been working well for me
Not likely. We add a hard-key jack to the Pride DX300 and leave the carrier key circuit still active. So long as the radio is holding the relay keyed it won't matter if the RF circuit is also active.
This does assume that the RF keying circuit is on the ground side of the relay coil. Older amplifiers would place the keying circuit between the hot wire from the standby switch and the relay coil. Not a common thing to see these days.
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well i got it all figured out and working thanks to and with the help of linear one. it turns out the keying circuit was made improperly and poorly. i completely removed it and installed a manual keying jack. the relay is operating properly now without the keying circuit. i am going to install a properly built keying circuit soon so if i want or need to rf key it i can do so. i will post a pic tomorrow of the install just for kicks. thanks for all the input guys on my quest to get this destroyed amp running again 
Here's the RF-sensing circuit we sell on fleabay.
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