[AMRadio] Navy TAJ-19 Transmitter
I have located the manual for the TAJ-19. Thank you for your replies. Bob, K2GLO __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[AMRadio] Navy TAJ-19 Transmitter
HELP !! I am looking for a schematic and information for a Navy ship TAJ-19 transmitter that I recently acquired. It was made by General Electric in 1944 and uses one 861 in the Final and three 860's. Any leads on where I can get information for it would be most helpful. I have found some information and a partial schematic on the TAJ-18 which is a similar transmitter but not the same. Thanks Bob, K2GLO __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[AMRadio] Testing High Voltage Diode Blocks
There have been some comments about H.V. diodes not testing but seem to be ok. I assume that people are testing them with the diode function of a digital multimeter. Typically, a H.V. diode has a number of diodes in series within it which makes it have a higher voltage drop than a normal diode. Because of the higher voltage drop, a digital multimeter show them as defective. A crude and simple go - no go way of testing a H.V. diode is to hook the diode block in series with a 120V lamp and apply 120V to the diode - lamp series combination. If the lamp does not light, the diode is open. If the lamp lights at about half brilliance, the diode can be assumed to be good. If the lamp lights at full brilliance, the diode can be assumed to be shorted. Obviously, be very careful when working around line voltage. Bob, K2GLO __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] RE Electronic Capacitor Reforming
There has been alot of discussion regarding electrolytic capacitor leakage. Here are the official specifications. The JAN-C-62 specification addresses the maximum acceptable allowable leakage for electrolytic capacitors. (There is also an EIA specification but it is the same as Jan-C-62). The formula is I = (K)(C)+0.3 where I is the maximum allowable leakage current in milliamperes, C is the capacitance in ufd, and K is a constant relative to the working voltage of the electrolytic capacitor. K = 0.01 for voltages up to 100 volts; K = 0.02 for working voltages between 101 and 250 volts; K = 0.025 for working voltages between 251 and 350 volts; and K = 0.04 for working voltages between 351 and 450 volts. Here are some an examples, a 20 ufd @ 450 volt capacitor has a maximum acceptable allowable leakage current of (0.04)(20)+0.3 which works out to 1.1 ma.; while a 20 ufd @ 250 volts would have a maximum acceptable allowable leakage current of (0.02)(20)+0.0.3 which works out to 0.7 ma. K4KYV hit the nail on the head with his comment that the leakage must be proportional the the capacitance. As you see by the formula, the allowable leakage is proportional to the capacitance. It seams that everyone has their own opinion and method on reforming so I will throw method in the pot since it works well for me. I sell NOS can electrolytic cans so I built a couple custom reformers to condition them. One is for 150 volt cans and the other for 450 volt cans. Each reformer can reform up to 30 electrolytic sections at a time. I will only discuss the 450 volt reformer. It is basically a 450 volt supply that is regulated so it does not exceed 450 volts as the reforming currents decrease. Each of the 30 reforming legs has has a 90K current limiting resistor in series with the capacitor which limits the current to 5 ma in a short circuit condition. Typically an unreformed capacitor will draw about 2 to 3 ma initially and leakage current usually drops of considerably in the first few hours. I can moniter the leakage current of each independent reforming leg with a 30 position switching system. The meter is switchable to read full scale currents of 8 ma, 1.6 ma, 0.8 ma and 0.16 ma. As an example, an unreformed capacitor that starts off drawing 2 ma will only have 270 volts applied to it because if the current limiting resistor. As the capacitor reforms, the leakage current decreases and the voltage increases upward to 450 volts. Many my 20 ufd capacitors will reform to leakage values well below 0.05 ma @ 450 volts. I typically reform my capacitors for 3 days and then in addition, operate them at a full 450 volts for an additional 4 to 7 days to endurance test them. One advantage of the 7 to 10 day reforming and endurance testing period is that on rare occasions some electrolytic fluid will weep through where the terminal pentrates the bottom seal. The extended testing period allows this condition to manifest itself. The 5 ma current limit is pretty safe and I have never had a capacitor explode on me even when they have had excessive leakage. I have reformed many capacitors using the above method I find the capacitors respond very well to this method. Bob, K2GLO __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Re: 6V6 vs 6L6
I agree that substituting a 6V6 for a 6L6 is quite a stretch. I am an active and founding member of the Tube Collectors Association, Inc. Over the years the topic of tube substitution guides has been discussed within our group. The general consensus is that there are numerous tube substitution stretches and downright misinformation in the literature. Sometimes it is just a simple alpha transposition such as 6AC7 v.s. 6CA7 (there is a big difference between those two tubes) and other times the recommended substitution totally incompatible. It is interesting to compare recommended tube substitutions by various authors and see how the authors differ in their substitution findings. In my opinion, a tube substitution guide is a valuable resource in homing in on possible replacements and no more than that. One should then review the published tube specifications of the intended replacement tube and determine its compatibility before making the substitution. While on the subject, as the demand for tubes waned and production decreased, manufacturers resorted to creative substitutions so they would not have to tool up for a particular tube. Here are some examples I have in my collection: a 6SQ7GT (octal based duodiode-triode) that obviously has the internal elements of a 7-pin miniature 6AV6 (duodiode-triode) complete with the mica wafers designed for a 7-pin miniature glass envelope. I also have a Sylvania 6J5GT (octal based medium mu triode) that has the internal structure of a 6SN7GT (octal based twin medium mu triodes). Only one of the twin triode sections is used and connected to the base in the 6J5GT configutation. The other triode section just sits there supporting the mica wafers and totally unconnected. More unusual, is a Sylvania 6SF5 (metal shell octal based triode). Inside the metal shell is a a 7-pin miniature 6AV6 (duodiode-triode) complete with a 7-pin miniature socket! The extra non-needed and unused duodiode elements of the 6AV6 are strapped to the cathode. What made this tube suspicious was the tall metal shell normally found on a metal 6V6. Another unusual one is a metal RCA 12SK7 that has inside it a 7-pin miniature tube which is assumed to be a unmarked 12BA6. Also interesting is that the 12BA6 tube has the four creases on the top of the glass envelope that is common to European tubes! So you can see the big boy manufacturers were scrambling to supply various tubes towards the end of the US tube manufacturing era. It is also interesting to note the industry's blatant mis-marking and deceptive production of various tubes. Jim Cross has on this web-site www.vacuumtubesinc.com a link that he authored and calls Vacuum Tubes, Inc., Hall of Shame. There he identifies various tubes that are Marked with the Intent to Deceive, Marked as a Suitable Substitution and Friday at the Tube Factory. His site is worth looking at. For those of you that seriously work tubes, there is a great reference book for both users and collectors alike called Tube Lore by Ludwell Sibley. I know Vacuum Tubes Inc. has that book available. Bob, K2GLO __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Stanwyck Contact
A few days ago, I requested information on the Stanwyck Winding Company. A gentleman contacted me by email outside the reflector and stated that he had worked there. Somehow his email got dumped before I could respond. I would appreciate another contact from that gentleman so I can correspond. Thanks, Bob K2GLO __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Stanwyck information wanted
Hello Guys: Do any of you have catalog information on inductors and related products manufactured by the STANWYCK Winding Company of Newburgh, New York? I am looking for information on their products manufactured during the early 1960's. Thanks, Bob K2GLO __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Coils
Hello Don I would like to purchase your Coil Forms and receiving coil Box ($140) and the box of and Mini-Ductors and Air-Dux coils ($75). Please tell me the total to 97520 Thanks, Bob K2GLO __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Re: Last Plea for Capacitor
Rick: I got excited when I found both a Sangamo 0.0001 and a .00015 Mfd. 2500 wdcv type A2 capacitor in the parts bin. However when I tested both of them they were both shorted. What a bummer! I also found a Cornell-Doublier type 9LSA 0.0001 Mfd. at 2500 wvdc that looks physically identical to the type A2. The only difference I see is in the terminal/mounting sleeves. The A2 has a threaded sleeve for a 6-32 screw while the 9LSA has smooth bore sleeve (unthreaded) with an i.d. that accepts a 6-32 screw. I tested it on my military ZM-3A/U capacitor analyzer and it tested fine. If the 9LSA will work in your application and you're interested in it, I will I will take the time to throw it across 2200 volts and cook it for a few hours to make sure that it won't break down under high voltage. You may email me off line. Bob, K2GLO __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
RE: [AMRadio] Triode connecting 803's for a Modulator
Thank you for the detailed information. I appreciate it. My friend is sending me copies of the Handbook article. It is great to have a responsive group like this with so much knowledge on tap. 73, Bob K2GLO
[AMRadio] Triode connecting 803's for a Modulator
I have a bunch of 803's. In the past, I have seen modulator articles featuring triode connected 813's. Physically, the 803 also looks like it would be a good candidate for the same application. Has anybody tried triode connecting 803's for a modulator? If so, what were the design parameters did you used? Tnx, Bob K2GLO
RE: [AMRadio] Millen 90902 info needed, please.
Craig: I have a 2-inch monitor scope that was built from a schematic that appeared in the 1950 ARRL Handbook, page 490. You might be able compare your circuit against that schematic and get a ballpark value for the capacitor you seeking information on. 73, Bob, K2GLO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dennis Pharr Sent: Thursday, February 23, 2006 5:04 PM To: 'Discussion of AM Radio' Subject: RE: [AMRadio] Millen 90902 info needed, please. Craig: You might find something useful on the James Millen Society webpage. Although they don't have a schematic for a 2 scope, they do have schematics for the 3 scope (90903) and the circuit may be similar such that you could identify the value of the cap - good luck. http://www.isquare.com/millen/millen-page.htm Dennis WD5JWY -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Roberts Sent: Thursday, February 23, 2006 2:55 PM To: Discussion of AM Radio Subject: [AMRadio] Millen 90902 info needed, please. Hey y'all -- I've just acquired a nice looking Millen 90902 2 monitor scope. It needs recapping, however. One of the caps is an oil filled device that's leaked its contents. I think it's a good candidate for replacement :-) The problem is, I can't read its value (the label's destroyed) and I don't have a schematic for this scope. Does anyone know what this cap is...or what might be a decent substitute. It needs a 1 KV rating. Many thanks and 73, Craig W3CRR __ 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 __ 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
[AMRadio] Re: AM Transmitter Advice??
To Jim, John and all: Jim: The URL you listed is a great site for information on the HK type 5. It is quite true that the HK type 5 never went much beyond the prototype stage and I have one of those rare little puppies in my collection. However, the larger transmitting gridless Gammatrons were used extensively in the west coast based Globe Wireless communication system built by HK. The complete HK gridless Gammatron story is about a 30-page article named Defiance in the West, The Heintz and Kaufman Story that was published in the AWA Review, Volume X, 1996. It includes pictures of all the different gridless Gammatrons. John: The 6AX5GT and some Raytheon 6X5WGT's have the proper plate-cathode construction that makes them candidates for gridless Gammatron experimentation. I can not take credit for the initial idea of using the 6AX5GT. Reed Fisher, W2CQH, first introduced the use of the 6AX5GT as an experimental gridless Gammatron substitute in an article that appeared in the April, 2004 issue of the Tube Collector. I refer to both his work and the above mentioned AWA Review article in my article that appears in the February, 2006 Tube Collector. Using the above information, I further refined the 6AX5GT Gammatron operating conditions and developed the AM transmitter circuit. My article documents my experimental findings and includes the AM transmitter schematic. In a nutshell and just enough to peak your interest into pursuing the articles for all the details, I offer the brief description of operation: One must reduce the heater voltage of the 6AX5GT to a point the there is a limited flow of electrons between cathode and one of the two plates that has been selected to act as the anode. About 15 ma. appears to be optimum in my circuits with 75 volts on the anode. The second plate is then used as the Gamma or control plate which is synonymous with the grid connection in a triode circuit. Control potentials imposed on the designated Gamma plate diverts some of the cathode to anode electron flow to the Gamma plate therefore causing triode action. A word of caution! Since one has a forward biased diode across the power supply with only the cathode temperature limiting the electron flow, one must protect the power supply from the possibility of excessive current. Initially, I used a #47 lamp in series with the anode and the power supply. I got tired of replacing the lamps when I was experimenting with various Gamma currents or electron space charge buildup and resorted to a voltage divider setup allowing 75 volts at 15 ma. from a 180 volt supply. The design wattage of the voltage dropping resistor was selected so it could safely dissipate the entire 180 volts in conditions when the Gammatron currents became excessive either due to too high of a heater voltage or electron space charge buildup. I suggest that you visit http://www.tubecollectors.org/ for information regarding the tube collector. I just noticed that the editor has not listed the February, 2006 on the website yet. However, all previous issues are currently listed. Information on the most recent issue containing my article should be appearing in the next couple days. Have fun experimenting That is what ham radio is all about. Bob, K2GLO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Candela Sent: Friday, February 17, 2006 4:09 AM To: Discussion of AM Radio Subject: RE: [AMRadio] Re: AM Transmitter Advice?? John, Check this out: http://uv201.com/Tube_Pages/heintz-kaufman.htm Jim WD5JKO --- John Coleman ARS WA5BXO [EMAIL PROTECTED] wrote: OK BOB! You got my attention. Explain more. I hope I'm not a sucker here. I have seen and extremely low mu amplifier circuit (common cathode) made by reverse biasing the plate of a triode and forward biasing the grid where output is taken from the grid and input is on the plate. So I know that weird stuff does exist. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bob Deuel Sent: Thursday, February 16, 2006 6:05 PM To: 'Discussion of AM Radio' Subject: [AMRadio] Re: AM Transmitter Advice?? Hello Larry and all: Larry's tongue in cheek comment employing 866's as a linear amplifier tube prompted me to contribute the following: Certain full-wave rectifiers can be configured to amplify or oscillate. I have built audio, Hartley and Simpson oscillators using only 6AX5GT's full-wave rectifiers as the sole active device. These were displayed at 2004 Mid-Atlantic Antique Radio Club Meet and actually won a Blue Ribbon. Late last year I built an AM transmitter consisting of a Hartley oscillator modulated by an AM modulator using only 6AX5GT full-wave rectifier tubes as the active devices. No solid-state magic, just simple full-wave rectifiers. The basic concept is that of the Heintz and Kaufman gridless Gammatron circuits
[AMRadio] Re: AM Transmitter Advice??
Hello Larry and all: Larry's tongue in cheek comment employing 866's as a linear amplifier tube prompted me to contribute the following: Certain full-wave rectifiers can be configured to amplify or oscillate. I have built audio, Hartley and Simpson oscillators using only 6AX5GT's full-wave rectifiers as the sole active device. These were displayed at 2004 Mid-Atlantic Antique Radio Club Meet and actually won a Blue Ribbon. Late last year I built an AM transmitter consisting of a Hartley oscillator modulated by an AM modulator using only 6AX5GT full-wave rectifier tubes as the active devices. No solid-state magic, just simple full-wave rectifiers. The basic concept is that of the Heintz and Kaufman gridless Gammatron circuits. The transmitter was set up for the broadcast band and works fine. It has been publicly demonstrated a couple times now and a write up including the circuit was published in the February, 2006 issue of the Tube Collector magazine which is the bi-monthly magazine published by the Tube Collectors Association, Inc. It is fun to make full-wave rectifiers do more than just rectify. Bob, K2GLO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of ne1s Sent: Thursday, February 16, 2006 10:36 AM To: Discussion of AM Radio Subject: [AMRadio] Re: AM Transmitter Advice?? Donald Chester writes: Assuming one is going to build a linear, and so putting aside other issues such as linear vs plate modulation, why do you think it makes a difference what tube is used? Are you referring to running a linear at greater than legal limit?. Well, go ahead and try building a legal limit linear that runs a pair of 807's in the final. Yeah, or a pair of 866As Sorry (the devil made me do it). 73, -Larry/NE1S __ 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
