Re: [AMRadio] would like to build a little homebrew project

2007-07-30 Thread WE0H
That's exactly what I want to do. Low power using receive type tubes to start with then go for higher powered building. Mike WE0H Jason Buchanan wrote: I'm wanting to build a little homebrew project and build bigger ones based on what I learn from the smaller project. Just wondering if any

Re: [AMRadio] would like to build a little homebrew project

2007-07-30 Thread Greg
What power level are you thinking about? What features and what is the modulation scheme? I have a bunch of older left coast and ARRL handbooks that may have what you are looking for. I may be able to locate something for you and scan it to you. Greg WA7LYO Kinston NC - Original Message ---

[AMRadio] would like to build a little homebrew project

2007-07-30 Thread Jason Buchanan
I'm wanting to build a little homebrew project and build bigger ones based on what I learn from the smaller project. Just wondering if anyone could point me in the right direction for building a nice little AM transmitter, preferably for use on 160 meters... I guess I need to find some

RE: [AMRadio] Subj change - HB designs

2007-07-30 Thread John Coleman
Bret: First let me point out that the centertap of a XFMR does not represent 1/2 of the load resistance but only 1/4. That is to say that if a 2500 ohm near perfect match is made from the output of a XFMR and the load is to be moved to the centertap using only 1/2 the winding, the load resistanc

Re: [AMRadio] Subj change - HB designs

2007-07-30 Thread Geoff/W5OMR
Brett gazdzinski wrote: But is there any advantage over the 8 ohm to grid setup? The disadvantage is a lot of complexity, additional power supplies, transistors that can fail, heat sinks, etc A lump of iron is a lot simpler... If you don't mind the hysteresis loss and subsequent cross-

RE: [AMRadio] Subj change - HB designs

2007-07-30 Thread Brett gazdzinski
But is there any advantage over the 8 ohm to grid setup? The disadvantage is a lot of complexity, additional power supplies, transistors that can fail, heat sinks, etc A lump of iron is a lot simpler... Brett N2DTS > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PR

Re: [AMRadio] Subj change - HB designs

2007-07-30 Thread Geoff/W5OMR
Brett gazdzinski wrote: Think that circuit is better then a hifi transformer (say 2500 ohms center tapped) to 8 ohms? 8 ohm side goes to the hifi amp, the 2500 ohm side goes to the grids. Swamping resistors go across the 2500 ohm side (1250 ohms to center tap) http://www.qsl.net/wa5bxo/drive

RE: [AMRadio] Re: VK1 813 rig

2007-07-30 Thread Brett gazdzinski
A 4D32 is good for about 100 watts of carrier out, but to get good modulation peaks, they seem to like higher plate voltages, above 800 volts say. I am not sure if it's the screen or a lack of peak emission, but I find if you run them at say 600 volts they just don't make a lot of positive peaks.

RE: [AMRadio] Subj change - HB designs

2007-07-30 Thread Brett gazdzinski
Think that circuit is better then a hifi transformer (say 2500 ohms center tapped) to 8 ohms? 8 ohm side goes to the hifi amp, the 2500 ohm side goes to the grids. Swamping resistors go across the 2500 ohm side (1250 ohms to center tap) Brett N2DTS > -Original Message- > From: [EMAIL PR