[AMRadio] Central Electronics 20A QRO#3 Project
Hi Group, This is a first draft containing some results using Yogi's (KC5MIP) 20A after QRO conversion. More info and schematics will follow. http://pages.prodigy.net/jcandela/CE20AQRO/20AQRO3.doc Be Kind, Jim WD5JKO --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.772 / Virus Database: 519 - Release Date: 10/1/2004
[AMRadio] SpaceShip One uses AM
Nitrous oxide is a powerful oxidizer. During ancient times when you could buy the stuff and nobody knew it was dangerous (and before sulphur dioxide was added in order to melt the lungs of anyone who 'gasses up'), I won many a bet, that I could burn a hole in an aluminum pie plate with a cigarette. 0. light cigarette (use a marlboro red or 100 with no holes in filter). 1. inhale nitrous 2. with cigarrette in mouth, bring pie plate up to coal. 3. exhale slowly through cigarette, turning its tip into a white hot torch. (haste wastes nitrous, sloth decreases temperature) 4. burn through the plate. the aluminum is consumed to ash. quite safe actually, unless you count the intoxication factor. The crazy stuff of the past.. whew. makes me wonder how I survived, stayed out of jail, and became successful. In any case, there's your field expedient torch. === From: [EMAIL PROTECTED] And the fuel is the reaction of rubber and nitrous oxide.
[AMRadio] ugly RBB cabinet wanted
Does not have to be pretty, but I would like one for my RBB prototype. Here's the rig.. http://208.190.133.201/vrps200309/vrps_swap_200309.html Patrick
[AMRadio] Re: AMRadio Digest, Vol 9, Issue 6
Jim, As a hi-fi amp, it is extremely clean and very flat from 20Hz to 20KHz up to about 80-100 watts. Above that, despite what the specs may say, heavy bass causes distortion due to the smallish size of the output transformer. As the point is approached, hum increases due to the transformer saturating. It is a first rate public address amp and a super modulator. I have looked into getting (having made) larger transformers to hadle 20-20K at 200W, but finding one with a 6500 ohm CT primary that will take the 930 volts DC is difficult. If I were to have them made, I would go for a 10K or 12K primary and change the power supply to solid state, add about 200uF of capacitors (mount where the 5R4's are), and eliminate the choke input (and the choke, to make room for the big transformer) for 1100-1200V on the plates. I have been quoted $400 each for such. I did experiment, simply bypassing the choke to get higher volts on the tubes, and got 240 watts, but the 'KLIXON' popped after a couple minutes, not from heat, but it also responds to current. I would not run them that way unless replacing the OPT's. I have only three, one is reserved for parts but is actually in working order less perhaps the tubes. Patrick From: "Jim candela" <[EMAIL PROTECTED]> Subject: RE: [AMRadio] Home brew AM Patrick, That Altec amplifier sure is nice! I really like the 5R4 full wave bridge rectifier with the extra filament taps off the HV windings. Never seen that done before. Also the 6W6 triode connected cathode follower stage is unique with the center tapped choke. I see negative feedback from the output tranny all the way back to the first preamp stage. Without getting too far into audio jargon, how do two of these beasts sound as a stereo amplifier? The HV filter only has 6 uf as part of a LC filter, so how is the bass response? Got a few dozen of these lying around? :) Regards, Jim Candela WD5JKO
Re: [AMRadio] Tube bake in process.
Run the filaments for a minimum of half hour before applying high voltage. You don't mention what tube you are speaking about, but if it is an Eimac, go to their website and read their technical information. http://www.cpii.com/eimac/index.html The information is good no matter who made the tube(s). According to RCA, run the tube filament only for 30 minutes. Then run it with reduced grid drive for 30 more minutes. Then run it at full grid drive and reduced plate voltage for 30 minutes. Finally run it at full grid drive and full plate voltage. Don K4KYV
Re: [AMRadio] Re: SpaceShip One uses AM
But of course don't forget that all the ATC over the ocean communications is SSB. - Original Message - From: "Mahlon Haunschild" <[EMAIL PROTECTED]> To: Sent: Wednesday, October 06, 2004 7:05 AM Subject: [AMRadio] Re: SpaceShip One uses AM > Fun fact: All aviation voice communications is AM, albeit VHF. > SpaceShip One isn't unique. > > It's AM because the blocking effect that FM exhibits is considered > unacceptable. With AM, if two stations interfere you can usually hear > both signals to some degree through the heterodyne. With FM, one > station would block the other. The flight safety boffins wouldn't like > that. > > SSB of course would be too labor-intensive for aviation service. > > regards, > > Mahlon - K4OQ
Re: [AMRadio] Old Lafayette Parts Wanted
Thanks, Pete, for the clarification on the differences between the 410 and the comstat connectors. If I can find a manual, I may have a power connector that I can convert. K5XU
[AMRadio] Re: SpaceShip One uses AM
Fun fact: All aviation voice communications is AM, albeit VHF. SpaceShip One isn't unique. It's AM because the blocking effect that FM exhibits is considered unacceptable. With AM, if two stations interfere you can usually hear both signals to some degree through the heterodyne. With FM, one station would block the other. The flight safety boffins wouldn't like that. SSB of course would be too labor-intensive for aviation service. regards, Mahlon - K4OQ -- Message: 12 Date: Wed, 6 Oct 2004 01:19:26 EDT From: [EMAIL PROTECTED] Subject: [AMRadio] SpaceShip One uses AM To: amradio@mailman.qth.net Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="US-ASCII" I just watched an online recording of the winning flight of the "Space Ship One" into space and noticed the communications (by the nature of the heterodynes when stations doubled) was good old Amplitude Modulation! And the fuel is the reaction of rubber and nitrous oxide. I love combinations of old and new tech... Steve WD8DAS [EMAIL PROTECTED]
[AMRadio] SpaceShip One uses AM
I just watched an online recording of the winning flight of the "Space Ship One" into space and noticed the communications (by the nature of the heterodynes when stations doubled) was good old Amplitude Modulation! And the fuel is the reaction of rubber and nitrous oxide. I love combinations of old and new tech... Steve WD8DAS [EMAIL PROTECTED]
Re: [AMRadio] Old Lafayette Parts Wanted
The Comstat series of transceivers used 8 pin plug for the AC and DC connections, whereas the HA-410/460 used an 11 pin plug. Each AC and DC also had an unique set of jumper pins wired. Also, although the mikes for both rigs looked the same, the plugs were wired differently. A D-104 with push-to-talk stand works very well on the 410. Also a Turner +2, +3 and similar variants, along with the 254C work well with the 410. Plug needs to wired accordingly. Pete, wa2cwa, www.manualman.com ps manuals are available On Tue, 5 Oct 2004 18:07:17 -0500 "Mike Duke, K5XU" <[EMAIL PROTECTED]> writes: > > I am in need of the ac and or dc power cords and the microphone from > a > Lafayette HA410 or HA460 transceiver. I believe these same cords and > > microphone were > used on the Comstat 25 series of cb equipment. > > I also need the manual for the HA410. > > If you have any of these items in your junk box, let's please deal. > > Mike Duke, K5XU > American Council of Blind Radio Amateurs Get your name as your email address. Includes spam protection, 1GB storage, no ads and more Only $1.99/ month - visit http://www.mysite.com/name today!
