Re: [AMRadio] PA set up using ant analyzer
Hi Dennis; I am having trouble resonating the plate tank on the linear amplifier I just built. When checking for resonance with a grid dip meter using a 5,000 ohm resistor from plate to ground, should the tubes (4-400 X 2) be in the circuit? Also, the plate coil has 18 turns vertically and 5 turns horizontally for 10 meters. If I couple the GDO to the small coil will it see 80 meters? Thanks, Ed Richards K6UUZ
Re: [AMRadio] PA set up using ant analyzer
- Original Message - From: Edward B Richards [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, June 08, 2006 5:48 PM Subject: Re: [AMRadio] PA set up using ant analyzer Hi Dennis; I am having trouble resonating the plate tank on the linear amplifier I just built. When checking for resonance with a grid dip meter using a 5,000 ohm resistor from plate to ground, should the tubes (4-400 X 2) be in the circuit? This is not Dennis but the answer is the tubes must be there or a capacitor equal to the total output capacity of the tubes in their place. i.e.28 pf ( 14 each) for a pair of 813's check tube table for output cap. The analyzer should show a 1 to 1 swr from the antenna looking in when it is resonated. The grid dipper technique is differnet. You take the resonate plate load z , plate volts divided by 2 time plate current and divide by disired operating Q, 10 or so for the input capacitor, with the tank cold disconnected. use a capacity meter to set the C1 and then leave it alone, the output cap C2 is the load z ( 50) divided by q, about 2. These give the x sub c value which must be converted to capacity. Then you tap ( short coil till the analyzer shows one to one from the output jack). Hope this helps..For pi-network. check ARRL handbook for pi-l. Mike
RE: [AMRadio] PA set up using ant analyzer
Does it matter the type of tube, 833 or 592 r Thanks Brad -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mike Dorworth, K4XM Sent: Sunday, June 04, 2006 5:22 PM To: Discussion of AM Radio Subject: Re: [AMRadio] PA set up using ant analyzer - Original Message - From: uvcm inc. [EMAIL PROTECTED] To: AMRadio@mailman.qth.net Sent: Sunday, June 04, 2006 8:13 PM Subject: [AMRadio] PA set up using ant analyzer Does anyone know what value resistor between the plate of and ground for a 833 and a 892r, so I can set up the tank using an antenna analyzer like a mfj 369? The resistor value is determined (exactly) from the platevoltage divided by 2 times the plate current.. About 5000 ohms or so. __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.8.1/355 - Release Date: 6/2/2006
Re: [AMRadio] PA set up using ant analyzer
In a message dated 6/4/06 8:13:09 PM, [EMAIL PROTECTED] writes: Does it matter the type of tube, 833 or 592 r What's a 592 r tube? Can't find it in Fathauer or Sibley. See references to a 592 and a 592/3-200A3 but neither looks like a substitute for an 833. Dennis D. W7QHO Glendale, CA
Re: [AMRadio] PA set up using ant analyzer
The resonate plate load is the same for any class C amplifier, plate voltage divide by 2 times plate current. It is one half of the modulating inpedance. It is the same for a 6V6, 6AQ5 or a pair of 4-1000's.. Mike - Original Message - From: uvcm inc. [EMAIL PROTECTED] To: 'Mike Dorworth, K4XM' [EMAIL PROTECTED]; 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Sunday, June 04, 2006 11:12 PM Subject: RE: [AMRadio] PA set up using ant analyzer Does it matter the type of tube, 833 or 592 r Thanks Brad -
Re: [AMRadio] PA set up using ant analyzer
- Original Message - From: uvcm inc. [EMAIL PROTECTED] To: AMRadio@mailman.qth.net Sent: Sunday, June 04, 2006 8:13 PM Subject: [AMRadio] PA set up using ant analyzer Does anyone know what value resistor between the plate of and ground for a 833 and a 892r, so I can set up the tank using an antenna analyzer like a mfj 369? The resistor value is determined (exactly) from the platevoltage divided by 2 times the plate current.. About 5000 ohms or so.
