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Gordonp: /* How To Tune */

2021-01-04T22:15:28Z

How To Tune

← Older revision		Revision as of 22:15, 4 January 2021
Line 66:		Line 66:
	<li><b>TUNE</b> knob adjusted to give a Screen Current <b>PEAK</b> This peak could be any value; often the meter begins by reading hard-left (below 0), and a "peak" is any indication higher than this.</li>		<li><b>TUNE</b> knob adjusted to give a Screen Current <b>PEAK</b> This peak could be any value; often the meter begins by reading hard-left (below 0), and a "peak" is any indication higher than this.</li>
	<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign Screen Current back in closer to '0'</li>		<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign Screen Current back in closer to '0'</li>
	<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li~~></ul~~>		<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li>
			<li><b>Reduce</b> the screen-current peak by <b>Increasing</b> the Loading dial numbers; <b>Increase</b> the screen-current peak by <b>Decreasing</b> the Loading dial numbers</li></ul>
	<br>		<br>
	Too much drive when the amp is not loaded heavily enough will cause the screen current to go very high. Load the amp more by reducing the LOADING Capacitance (turn knob clock-wise / higher numbers)		Too much drive when the amp is not loaded heavily enough will cause the screen current to go very high. Load the amp more by reducing the LOADING Capacitance (turn knob clock-wise / higher numbers)

Gordonp: /* How To Tune */

2020-11-30T18:53:28Z

How To Tune

← Older revision		Revision as of 18:53, 30 November 2020
Line 65:		Line 65:
	<li><b>DRIVE</b> increase slightly to give some Plate Current, then quickly</li>		<li><b>DRIVE</b> increase slightly to give some Plate Current, then quickly</li>
	<li><b>TUNE</b> knob adjusted to give a Screen Current <b>PEAK</b> This peak could be any value; often the meter begins by reading hard-left (below 0), and a "peak" is any indication higher than this.</li>		<li><b>TUNE</b> knob adjusted to give a Screen Current <b>PEAK</b> This peak could be any value; often the meter begins by reading hard-left (below 0), and a "peak" is any indication higher than this.</li>
	<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign in back in closer to '0'</li>		<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign Screen Current back in closer to '0'</li>
	<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li></ul>		<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li></ul>
	<br>		<br>

Gordonp: /* How To Tune */

2020-11-28T19:49:18Z

How To Tune

← Older revision		Revision as of 19:49, 28 November 2020
Line 42:		Line 42:
	The takeaway: factor in your entire situation, if you even blink-think about striving for increased output		The takeaway: factor in your entire situation, if you even blink-think about striving for increased output
	<br><br>		<br><br>
			<hr>

	<b>Plate Dip Method</b><br>		<b>Plate Dip Method</b><br>
	This is always a good, safe method:		This is always a good, safe method:
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	This same method works with transmitters using tube-finals. For several decades, I used Heathkit, Yaesu, my own home-built transmitters, several amplifiers and other radios from the 60's and 70's - this was the manufacturer's described method of tuning too.		This same method works with transmitters using tube-finals. For several decades, I used Heathkit, Yaesu, my own home-built transmitters, several amplifiers and other radios from the 60's and 70's - this was the manufacturer's described method of tuning too.
	<br>		<br><br>
	<br>		<hr>

	<b>Screen Peak Method</b><br>		<b>Screen Peak Method</b><br>
	My favourite! This method is a bit tricky until you are accustomed to it, but gives the sharpest, most-accurate tuning, and is the most tube-friendly. It relies on the fact that tetrode operating-conditions can be clearly seen in the behaviour of the Screen Current. And fortunately for us, Collins included Screen Current metering!! It is also helpful for you to understand that the Screen Current is OK to flow in or out of the tube... both directions of Screen Current are possible and do happen (the Screen Supply must be able to source and also sink current).<br>		My favourite! This method is a bit tricky until you are accustomed to it, but gives the sharpest, most-accurate tuning, and is the most tube-friendly. It relies on the fact that tetrode operating-conditions can be clearly seen in the behaviour of the Screen Current. And fortunately for us, Collins included Screen Current metering!! It is also helpful for you to understand that the Screen Current is OK to flow in or out of the tube... both directions of Screen Current are possible and do happen (the Screen Supply must be able to source and also sink current).<br>
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	<br>		<br>
	Too much drive when the amp is not loaded heavily enough will cause the screen current to go very high. Load the amp more by reducing the LOADING Capacitance (turn knob clock-wise / higher numbers)		Too much drive when the amp is not loaded heavily enough will cause the screen current to go very high. Load the amp more by reducing the LOADING Capacitance (turn knob clock-wise / higher numbers)
	<br>		<br><br>
	This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.		This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.
	<br><br>		<br><br>
			<hr>

	<b>Maximum Smoke Method</b><br>		<b>Maximum Smoke Method</b><br>

Gordonp: /* How To Tune */

2020-11-28T19:48:28Z

How To Tune

← Older revision		Revision as of 19:48, 28 November 2020
Line 64:		Line 64:
	<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign in back in closer to '0'</li>		<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign in back in closer to '0'</li>
	<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li></ul>		<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li></ul>
			<br>
			Too much drive when the amp is not loaded heavily enough will cause the screen current to go very high. Load the amp more by reducing the LOADING Capacitance (turn knob clock-wise / higher numbers)
			<br>
	This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.		This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.
	<br><br>		<br><br>

Gordonp: /* How To Tune */

2020-11-28T19:45:18Z

How To Tune

← Older revision		Revision as of 19:45, 28 November 2020
Line 64:		Line 64:
	<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign in back in closer to '0'</li>		<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign in back in closer to '0'</li>
	<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li></ul>		<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li></ul>
	This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the ~~tube is at resonance,~~ tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.		This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.
	<br><br>		<br><br>

Gordonp: /* How To Tune */

2020-11-28T19:44:03Z

How To Tune

← Older revision		Revision as of 19:44, 28 November 2020
Line 52:		Line 52:
	<li><b>Plate Current</b> held to 300mA - 350mA, which is about the rated 1kW DC input it was designed for. You're done when you hit this desired Plate Current. If you have a Wattmeter, it should have a healthy reading (in the neighbourhood of 600W, maybe) and it should have shown approximately a peaking as you dip the plate.</li></ul>		<li><b>Plate Current</b> held to 300mA - 350mA, which is about the rated 1kW DC input it was designed for. You're done when you hit this desired Plate Current. If you have a Wattmeter, it should have a healthy reading (in the neighbourhood of 600W, maybe) and it should have shown approximately a peaking as you dip the plate.</li></ul>

	This same method works with transmitters using tube-finals. For several decades, I used Heathkit, Yaesu, home-built and other radios from the 60's and 70's ~~and~~ this was the manufacturer's described method of tuning too.		This same method works with transmitters using tube-finals. For several decades, I used Heathkit, Yaesu, my own home-built transmitters, several amplifiers and other radios from the 60's and 70's - this was the manufacturer's described method of tuning too.
	<br>		<br>
	<br>		<br>

Gordonp: /* How To Tune */

2020-11-28T19:41:37Z

How To Tune

← Older revision		Revision as of 19:41, 28 November 2020
Line 74:		Line 74:
	<li><b>DRIVE</b> increase slightly to give some Plate Current, then quickly</li>		<li><b>DRIVE</b> increase slightly to give some Plate Current, then quickly</li>
	<li><b>TUNE</b> knob adjusted to give Maximum RF Output as shown on your wattmeter, neighbour's RFI, whatever :-)</li>		<li><b>TUNE</b> knob adjusted to give Maximum RF Output as shown on your wattmeter, neighbour's RFI, whatever :-)</li>
	<li>Successively tweak LOADING, DRIVE power, and TUNING to achieve an output power you know is "about right", maybe based on prior experience. This could reasonably be 600W - 750W for a 4CX1000A, or as much as twice that for a 4CX1500B with raised Screen Voltage.</li>		<li>Successively tweak LOADING, DRIVE power, and TUNING to achieve an output power you know is "about right", maybe based on prior experience. This could reasonably be 600W - 750W for a 4CX1000A, or as much as twice that for a 4CX1500B with raised Screen Voltage.</li></ul>
	For the Maxium Smoke method, bear in-mind the tube-dissipation limits (affected by stock or modified blower), and the HV Power Supply - the HV power supply is good for 2200W ICAS / 1400W CCS... very robust for Collins' original 1kW DC input to the plate, but less-robust if you push harder, or operate high-duty-cycle / high-duty-factor modes.		For the Maxium Smoke method, bear in-mind the tube-dissipation limits (affected by stock or modified blower), and the HV Power Supply - the HV power supply is good for 2200W ICAS / 1400W CCS... very robust for Collins' original 1kW DC input to the plate, but less-robust if you push harder, or operate high-duty-cycle / high-duty-factor modes.

Gordonp: /* How To Tune */

2020-11-28T19:41:18Z

How To Tune

← Older revision		Revision as of 19:41, 28 November 2020
Line 63:		Line 63:
	<li><b>TUNE</b> knob adjusted to give a Screen Current <b>PEAK</b> This peak could be any value; often the meter begins by reading hard-left (below 0), and a "peak" is any indication higher than this.</li>		<li><b>TUNE</b> knob adjusted to give a Screen Current <b>PEAK</b> This peak could be any value; often the meter begins by reading hard-left (below 0), and a "peak" is any indication higher than this.</li>
	<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign in back in closer to '0'</li>		<li><b>DRIVE & LOADING</b> are alternately increased, then <b>Re-PEAK</b> Screen Current. At some point, you may find the Screen Current hard-right; this is a sure indication to focus on LOADING adjustment, to reign in back in closer to '0'</li>
	<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li>		<li>Your <b>Goal:</b> to get your desired Plate Current / Output Power, and find a LOADING point that produces a TUNING peak of 0. You are a puppet-master :-)</li></ul>
	This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the tube is at resonance, tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.		This can seem challenging at times, because it's sensitive to your antenna-impedance, the Pi-output-network settings, Plate Voltage and Plate Current. But when you get it, you can feel great knowing that the tube is at resonance, tube impedance is transformed nicely to (conjugately) match whatever craziness your antenna presents, and the output-power is maximized.
	<br><br>		<br><br>

	<b>Maximum Smoke Method</b><br>		<b>Maximum Smoke Method</b><br>
	This tongue-in-cheek term really means "peak for maximum output". It's fast, it's simple, and for modest in-band frequency changes, it's a reasonable way to tweak and re-adjust the 30S-1. It's just not a great primary-tune-up method.<br>		This tongue-in-cheek term really means "peak for maximum output". It's fast, it's simple, and for modest in-band frequency changes, it's a reasonable way to tweak and re-adjust the 30S-1. It's just not a great primary-tune-up method.<br>

Gordonp: /* How To Tune */

2020-11-28T19:39:34Z

How To Tune

← Older revision		Revision as of 19:39, 28 November 2020
Line 38:		Line 38:
	The general principle: start with reduced-drive, then work up to your desired power-level. Never let things get out-of-hand. For the 30s-1 and the 4CX1000A tube, stick to 0 grid-current! Normally, with a good tube, you will neither need it, nor have it; decrepit tubes may show notable grid-current which will seal their fate :-(		The general principle: start with reduced-drive, then work up to your desired power-level. Never let things get out-of-hand. For the 30s-1 and the 4CX1000A tube, stick to 0 grid-current! Normally, with a good tube, you will neither need it, nor have it; decrepit tubes may show notable grid-current which will seal their fate :-(
	<br><br>		<br><br>
	The 30S-1 was originally designed for 1kW DC input; given it's efficiency, this may produce 600W output, meaning 400W dissipated in the 4CX1000A tube. This is further reduced by your Mode - the duty-cycle / duty-factor will reduce the tube-dissipation even futher. Very Conservative! On the other hand, environmental factors like elevation will drastically reduce the cooling ability, and the normally-conservative 30S-1 design will become borderline :-O :-( ~~The takeaway: factor in your entire situation.~~		The 30S-1 was originally designed for 1kW DC input; given it's efficiency, this may produce 600W output, meaning 400W dissipated in the 4CX1000A tube. This is further reduced by your Mode - the duty-cycle / duty-factor will reduce the tube-dissipation even futher. Very Conservative! On the other hand, environmental factors like elevation will drastically reduce the cooling ability, and the normally-conservative 30S-1 design will become borderline :-O :-(
			<br><br>

			The takeaway: factor in your entire situation, if you even blink-think about striving for increased output
			<br><br>
	<b>Plate Dip Method</b><br>		<b>Plate Dip Method</b><br>
	This is always a good, safe method:		This is always a good, safe method:

Gordonp: /* How To Tune */

2020-11-28T19:38:33Z

How To Tune

← Older revision		Revision as of 19:38, 28 November 2020
Line 37:		Line 37:

	The general principle: start with reduced-drive, then work up to your desired power-level. Never let things get out-of-hand. For the 30s-1 and the 4CX1000A tube, stick to 0 grid-current! Normally, with a good tube, you will neither need it, nor have it; decrepit tubes may show notable grid-current which will seal their fate :-(		The general principle: start with reduced-drive, then work up to your desired power-level. Never let things get out-of-hand. For the 30s-1 and the 4CX1000A tube, stick to 0 grid-current! Normally, with a good tube, you will neither need it, nor have it; decrepit tubes may show notable grid-current which will seal their fate :-(
	<br>		<br><br>
	The 30S-1 was originally designed for 1kW DC input; given it's efficiency, this may produce 600W output, meaning 400W dissipated in the 4CX1000A tube. This is further reduced by your Mode - the duty-cycle / duty-factor will reduce the tube-dissipation even futher. Very Conservative! On the other hand, environmental factors like elevation will drastically reduce the cooling ability, and the normally-conservative 30S-1 design will become borderline :-O :-(		The 30S-1 was originally designed for 1kW DC input; given it's efficiency, this may produce 600W output, meaning 400W dissipated in the 4CX1000A tube. This is further reduced by your Mode - the duty-cycle / duty-factor will reduce the tube-dissipation even futher. Very Conservative! On the other hand, environmental factors like elevation will drastically reduce the cooling ability, and the normally-conservative 30S-1 design will become borderline :-O :-( The takeaway: factor in your entire situation.

	<b>Plate Dip Method</b><br>		<b>Plate Dip Method</b><br>