[AMRadio] DX-100B Low Output on 15 and 10 Meters
Folks -- I'm getting low output on 10 and 15 Meters. Typical output on the other lower bands is well over 100 Watts. All tubes test good, and I re-did the Buffer Coil adjustments as per the manual. After tune up on 15 Meters, here's my readings: Driver current is at 6 ma Ig is at 2 ma Ip is 250 ma Output power 50 W After tune up on 10 Meters, my readings are: Driver current is at 6 ma Ig is at 2 ma Ip is 250 ma Output power 65 W As a reference, after tune up on 20 meters, my readings are Driver current is at 6 ma Ig is at 6.5 ma Ip is 250 ma Output power 130 W Just for "fun", on both 15 and 10, I upped the driver current to max, which was 10 and 7 mA respectively. The respecitve Ig's were 10+ and 5 mA, and the output power (both bands) jumped to 80W. So, seems I have a problem with the grid current on 10 and 15 M. I figure I'd start looking at the circuit around the Driver section of the bandswitch. I was wondering, though, is this a known problem with the DX-100B that might be attributed to (perhaps) neutralization? Any and all comments welcome. Thanks & 73 Mark K3MSB
Re: [AMRadio] K1MAN Enforcement and WINLINK
that AHole keyed up Right on top of the Boy scout jamboee On the air station last night.. would have been a good night for Lightning on his antennas. Patrick Jankowiak wrote: if you look up K1MAN on the arrl page, you find several articles about trouble with the fcc. __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] SX-25 manual
Looking for an original or copy for this receiver. Thank you. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com Nets: 3805 Khz, Monday/Wednesdays 8 PM EDST 14250 Khz Saturday, 12 Noon EDST
Re: [AMRadio] K1MAN Enforcement and WINLINK
if you look up K1MAN on the arrl page, you find several articles about trouble with the fcc.
Re: [AMRadio] B&W 5100B Progress Update
Tom, Looks like you got it fixed. The way ham gear is (was/is?) sometimes made, things might have to be just right to get the specified performance. I don't know much about the B&W, but maybe without the original modulation transformer, ther match is not quite perfect, so therefore slightly less performance. I hate to suggest it, but if you run maybe 80 watts, how much modulation do you get? Just for curiosity, can you tell the parameters of the circuit if you have measured them? I'd be greatly interested in the numbers. Maybe something will suggest itself for imporvement under scrutiny if you want to go to the trouble of getting the data. AM mode carrier condition: -PA B+ volts -PA screen volts -PA Plate current -Power out -modulator plate current modulated conditions: (sinewave at maximum % obtainable without clipping in the modulator) -modulation % -PA B+ volts -PA Plate current -Modulator B+ volts -Modulator plate current -Modulator screen volts -Modulator bias volts -rms or average value of 120Hz ripple on B+ Physical: -Model # of replacement transformer -connections made for impedance selection -DC resistance and voltage of the entire B+ winding of the power transformer -DC resistance and value of any HV B+ choke -value of filter capacitance on B+ -rectifiers (two 5R4 I think you said?) Patrick From: "Tom Elmore" <[EMAIL PROTECTED]> Subject: [AMRadio] B&W 5100B Progress Update I finally had time this week to install the Stancor replacement modulation transformer for my B&W 5100B and have found a set of taps that work on both the primary and secondary windings. I can make full carrier output of at least 100 watts but the modulation is only making about 85 to 90 % before it starts to flatten out on the scope and distort. I have changed both the modulator and final set of tubes and still get about the same percentage of modulation. I was hoping to make at least 100% easily. Someone mentioned recently that this was a characteristic of this unit and I wonder if it's power supply limitations or some other factors. Thank You Tom Elmore KA1NVZ Anchorage, Alaska
Re: [AMRadio] B&W 5100B Progress Update
Great Tom. I worked a guy yesterday using a great sounding B&W 5100B out of Gray Court, SC - it was W4IT, Steve. Sent him a QSL card too. On 16 Oct 2004 at 17:35, Tom Elmore wrote: > I finally had time this week to install the Stancor replacement modulation > transformer for my B&W 5100B and have found a set of taps that work on both > the primary and secondary windings. I can make full carrier output of at > least 100 watts but the modulation is only making about 85 to 90 % before it > starts to flatten out on the scope and distort. I have changed both the > modulator and final set of tubes and still get about the same percentage of > modulation. I was hoping to make at least 100% easily. Someone mentioned > recently that this was a characteristic of this unit and I wonder if it's > power supply limitations or some other factors. > > Thank You > Tom Elmore KA1NVZ > Anchorage, Alaska > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net
