I finished building to Edd's specs, With the exeption of the 1uf cap being .05, the magenta line switch and the 1 meg being 47 k. It didnt work, it blew a 1.5 amp fuse, I checked no shorts. ( I did this without the audio input)
:I finished building to Edd's specs, With the exeption of the 1uf cap being .05, the magenta line switch and the 1 meg being 47 k. It didnt work, it blew a 1.5 amp fuse, I checked no shorts. ( I did this without the audio input)
Edd doesn't show a fuse....where in the circuit is it?
Try pulling the tubes and see if it blows another one. That should give some idea of where the gremlin lives.
Lewis
::Hi agian, I didnt want to continue the long post.
::I finished building to Edd's specs, With the exeption of the 1uf cap being .05, the magenta line switch and the 1 meg being 47 k. It didnt work, it blew a 1.5 amp fuse, I checked no shorts. ( I did this without the audio input)
:
:
:
:Edd doesn't show a fuse....where in the circuit is it?
:Try pulling the tubes and see if it blows another one. That should give some idea of where the gremlin lives.
:Lewis
Ian:
Do you think that the fuse is of such a small value and the capacitor that charges when power is first applied is large enough that the inrush of current might have blown the fuse? Also, cold filaments draw more current than hot ones, so that's why there are slow blow fuses, they will tolerate a surge of current before blowing.
Think about that for a while, and let's see if maybe your problem is a no-sweat, after all.
Lewis
:
:::Hi agian, I didnt want to continue the long post.
:::I finished building to Edd's specs, With the exeption of the 1uf cap being .05, the magenta line switch and the 1 meg being 47 k. It didnt work, it blew a 1.5 amp fuse, I checked no shorts. ( I did this without the audio input)
::
::
::
::Edd doesn't show a fuse....where in the circuit is it?
::Try pulling the tubes and see if it blows another one. That should give some idea of where the gremlin lives.
::Lewis
Are you using a solid state or tube type rectifier? If you are using a solid state rectifier, do you have it wired properly? The line on the rectifier should be facing the direction that the cathode of a tube type rectifier would face.
Also, though I'm sure that you know what is what on your transformers, be sure to ohm them out so that you know which side is the primary and which is the secondary.
T.
:Lewis has a point, though a 1.5 ampere fuse is usually large enough. Try a slow-blow fuse, though.
:
:Are you using a solid state or tube type rectifier? If you are using a solid state rectifier, do you have it wired properly? The line on the rectifier should be facing the direction that the cathode of a tube type rectifier would face.
:
:Also, though I'm sure that you know what is what on your transformers, be sure to ohm them out so that you know which side is the primary and which is the secondary.
:
:T.
Are you sure of the colors for the primary and secondary? Generally the primary (line) is black.
Radiodoc
***************
:The first 6j5 is being used as the rectifier, and the transfromers I have are color coded , yellow primary, and black secondary 2 thick and a thin center tap(not connected)
:
:
::Lewis has a point, though a 1.5 ampere fuse is usually large enough. Try a slow-blow fuse, though.
::
::Are you using a solid state or tube type rectifier? If you are using a solid state rectifier, do you have it wired properly? The line on the rectifier should be facing the direction that the cathode of a tube type rectifier would face.
::
::Also, though I'm sure that you know what is what on your transformers, be sure to ohm them out so that you know which side is the primary and which is the secondary.
::
::T.
:Ian,
:
:Are you sure of the colors for the primary and secondary? Generally the primary (line) is black.
:
:Radiodoc
:***************
:
:
::The first 6j5 is being used as the rectifier, and the transfromers I have are color coded , yellow primary, and black secondary 2 thick and a thin center tap(not connected)
::
::
:::Lewis has a point, though a 1.5 ampere fuse is usually large enough. Try a slow-blow fuse, though.
:::
:::Are you using a solid state or tube type rectifier? If you are using a solid state rectifier, do you have it wired properly? The line on the rectifier should be facing the direction that the cathode of a tube type rectifier would face.
:::
:::Also, though I'm sure that you know what is what on your transformers, be sure to ohm them out so that you know which side is the primary and which is the secondary.
:::
:::T.
Possibly ? just a matter of semantics……since the transformers are being utilized in two modes .
The standard color coding is for black to be the AC primary and yellow being the filament winding.
In this situation, the first transformer ….at the left…would follow this arrangement, but in the case of the second units use. its 12VAC winding would be designated as the primary, with the 120 VAC winding being the secondary.Put an ohmmeter to a unit and confirm the windings identity's for sure, very low ohms for the 12V winding...possibly upwards to ~100 ohms for the AC...120VAC..winding.
Sooooo any chance that the left transformer got hooked up with the Yellow wires of that winding going to the AC line via the fuse…
Thank Heaven for fuse-es-esses!.... if so, you should have experienced what is called in the trade as a hard blow, with that fuse element darkening up the glass quite severely, with your additional internal observation of link……link……WHAT link ?
Basically, if you had the unit blow its top on turn on, I would suspect the top info, if encompassing a 15 second time lag something related with the rectifier and on past it. While on that topic what are the DC working voltage specs on the electrolytics?
I will upgrade the working schematic in progress… with your supplied info…shortly.
73's de Edd
The yellow is about 1 ohm and the black around 35 ohms
I'll start rewireing it now.
The 49uf is a 33uf 160v and a 16uf 150v in parallel
:The Windings are reversed. The yellow is the secondary with the thin black wire as the center tap, and the 2 thicker black wires are the primary, big mix up on my part but a bad job at packaging also.
:
:The yellow is about 1 ohm and the black around 35 ohms
:
:I'll start rewireing it now.
Radiodoc
*************
:The box says primary has 2 wires(there are 2 yellow) Secondary has 3(there are 3 black wires, 2 thick, 1 thin)
:
::Ian,
::
::Are you sure of the colors for the primary and secondary? Generally the primary (line) is black.
::
::Radiodoc
::***************
::
::
:::The first 6j5 is being used as the rectifier, and the transfromers I have are color coded , yellow primary, and black secondary 2 thick and a thin center tap(not connected)
:::
:::
::::Lewis has a point, though a 1.5 ampere fuse is usually large enough. Try a slow-blow fuse, though.
::::
::::Are you using a solid state or tube type rectifier? If you are using a solid state rectifier, do you have it wired properly? The line on the rectifier should be facing the direction that the cathode of a tube type rectifier would face.
::::
::::Also, though I'm sure that you know what is what on your transformers, be sure to ohm them out so that you know which side is the primary and which is the secondary.
::::
::::T.
This should now provide an updated “work-in-progress” Schematic…as per the latest info feedback received from people.
Aside:
Can you hear me now?….
…..specifically:
As per the sets of tube filaments in that milliseconds timeframe of the power up-until fuse vaporization and that microburst of ~2KV P/P energy that they were hit with. They may have the jits for days!...lol
Working Schematic Reference:
73's de Edd
....And yes, the thin yellow wires are for 12 volts, with the thin black wire as a center tap.....typical for Radio Shack type transformers.
T.
I have been viewing this thread but didn't say anything. I wondered why 12 volt tubes weren't used. I believe I would have used a couple of 12J5s and a 12SA7 instead. However, 6-volt tubes may have been all he had.
Radiodoc
**************
:Perhaps, instead of using a 6SA7 and a resistor, use a 12SA7, which is more common, anyway, and draws less current.
:
:....And yes, the thin yellow wires are for 12 volts, with the thin black wire as a center tap.....typical for Radio Shack type transformers.
:
:T.
.....Also, he could use all 6 volt tubes and wire two in series across the 12 volts, and then wire the third across 1/2 of the 12 volt winding to the center tap, which would throw the winding out of balance a bit, but probably wouldn't upset anything. Either way, whether using this method, a combination of 6 and 12 volt tubes, or all 12 volt tubes, it would be better than a resistor for waste reasons.....though any method would work just fine.
T.
You should have several volts minus on pin 5 of the 6J5 oscillator tube if it is oscillating. If not you may have to reverse the leads on either the primary or secondary of the oscillator coil to get the tube to oscillate.
Radiodoc
***************
:Ok plugged it in. All the tubes lit up, the cd player did not burn, and the fuse didnt blow. I used a radio to check 3 bands, with no luck. On Edds drawing the larger side of the coil is in the plate circut, and the smaller in the cathode-screen circut, I have these reversed because someone on the other thread said to use the small side in the plate circut. I think this might be the problem, also how do I align the trimmers on each side of the coil to make it occilate at the correct frequency?
I have yet to find a radio with the larger of the two coils in the plate circuit......so I am betting that the small coil should be in the plate circuit for good inductive amplification--to promote good automatic oscillation.
T.
WHUT !!!! no ‘mo smoke and fusee flashie –flashie !...also…
Are in order on getting the unit up and working so quickly after solving the initial snag(s).
Will have to look into the “touchiness” and stability a bit later as any adjustments that you will be making to the osc coil and its associated tuning trimmer will be VERY toucheee- touchee anyhow, only being circumventable by possibly also incorporating an additional small value trimmer capacitor….~5-10 pf…..adjustable.
It would be in parallel with the cluster that you now have.
The idea being to initially find the specific freq spectra that you want to operate on and then replacing the “coarse “ adjustment caps with a fixed silver mica of their value and then using the very small variable cap to make precise vernier adjustment to the frequency. Even then, you use an insulated tool (or an insulated shaft connecting a knob to the trimmer) in order to make the adjustment so that any added capacitance of any metal touching the circuit will be avoided.
Now that you have a created RF signal, it might be the time to try my mentioned swapping of the grid pin connections to see which works the best, as per the feeding of RF into the lower 1st grid and using the other grid for the modulation input …OR..if you reverse the input functions and try it that way. Notice that I said that all of the discrete components associated with each grids..eg..their biasing and load resistors and coupling capacitors stay the same..just the pin connections to the circuitry get swapped for getting an evaluation of the improvement of modulation or RF amplification in that tubes circuitry…mainly the RF level.
The audio input modulation level can then be toyed with separately, should its degree of modulation be insufficient.
73's de Edd
:I did try to swap the grid inputs keeping all wiring the same, except the output of the .05 mfd cap, and the 100pf cap. The resistors did not move, and the 47k is a 1 meg (from 3rd grid to b-). I shielded the 6sa7, and the oscillator , which reduced the whistle. The grid swap did not change the output. Any ideas on how to reduce the amount of required antenna? Someone mentioned a 6j5 audio amp to boost gain and to eliminate the resistor on the one tube. Can the 1.2 amp transformer supply 4 tube heaters and the b+?
T.
Do you by chance have the plate of the 6J5 oscillator connected to the plate of the 6SA7? That would cause the problem you describe (touchy oscillator). Also, does your oscillator have a tunable powdered slug? If so, then you can adjust it as well as the trimmers (though adjusting it won't cure your problem).
The output of the 6SA7 shouldn't affect the oscillator. I've built a transmitter using just a 12SA7 (same as a 6SA7 except filament voltage), and it was perfectly stable. It was also strong enough to be received on a radio in the room. If you want to improve the output of your transmitter, you can build a loading coil. I found that the 100uH chokes that Radio Shack sells will work well as a loading coil with a tuning capacitor in parallel. I forgot what size tuning capacitor I used, but wire the two in parallel and wire them in series with the antenna. Then adjust the tuning capacitor until the signal gets really strong.
T.
T.
You should have enough gain with just the two stages, but the extra stage will help. You're most likely to improve things with a loading coil on the antenna (paralleled with a trimmer cap).
T.
:Will this work for the new 6j5 rf amp?
:
:
:I already have a xmitter from a kit, but this looks better and also seems more nostalgic. Would a very small cap between the antenna and the b- neutralize the whistle? Yes the cap listed is .75pf, but i have more trimmers to use instead, or will this cap neutalize the carrier. I did try this with metal tubes and it really didnt affect it much. As for the power output, even with the RF 6j5, I dont think it will go more than 500ft, I can't even get the signal on the 3rd from of my house(with out the Rf 6j5 and with a 500ft spool antenna). Also as a final question, This is safe to plug into a cd player headphone output, but is it safe to plug into my computers headphone output(No risk AT ALL)?
:
:
May try a small ceramic disc cap from B+ to B-. Something probably in the order of .005 or so. May try tacking it in at pin 4 of the 6SA7 to B- or cathode. May also try a small value cap from 6SA7 pin 8 (audio input) to B-. Only takes a few minutes to do this and see what happens.
Radiodoc
*************
:The 1.2 amp transformer is getting warm under 3 tube operation, and the 450ma transformer is cold always.
:
::I already have a xmitter from a kit, but this looks better and also seems more nostalgic. Would a very small cap between the antenna and the b- neutralize the whistle? Yes the cap listed is .75pf, but i have more trimmers to use instead, or will this cap neutalize the carrier. I did try this with metal tubes and it really didnt affect it much. As for the power output, even with the RF 6j5, I dont think it will go more than 500ft, I can't even get the signal on the 3rd from of my house(with out the Rf 6j5 and with a 500ft spool antenna). Also as a final question, This is safe to plug into a cd player headphone output, but is it safe to plug into my computers headphone output(No risk AT ALL)?
::
::
I read back thru this thread and I believe you mentioned the oscillator coil was in a can (metal?). I believe the oscillator can should be connected to the B- for proper operation.
Radiodoc
**************
:The 1.2 amp transformer is getting warm under 3 tube operation, and the 450ma transformer is cold always.
:
::I already have a xmitter from a kit, but this looks better and also seems more nostalgic. Would a very small cap between the antenna and the b- neutralize the whistle? Yes the cap listed is .75pf, but i have more trimmers to use instead, or will this cap neutalize the carrier. I did try this with metal tubes and it really didnt affect it much. As for the power output, even with the RF 6j5, I dont think it will go more than 500ft, I can't even get the signal on the 3rd from of my house(with out the Rf 6j5 and with a 500ft spool antenna). Also as a final question, This is safe to plug into a cd player headphone output, but is it safe to plug into my computers headphone output(No risk AT ALL)?
::
::
Attaching a loading coil in series with the antenn will work wonders in many cases. Don't expect the transmitter to broadcast too far throughout the house or yard, though. With those tubes it won't. If you want it to broadcast farther, for one thing use tuned RF transformers between the 6SA7 and the 6J5, and between the 6J5 and the antenna. Also, you might consider replacing the 6J5 with a 6K6, though you'll also need a bigger power transformer for that. In any case, if you use RF transformers, the universal kind can be obtained from www.tubesandmore.com. The small coils should be in the plate circuits, and the large coils should be in the grid circuits, or feeding the antenna. The large coils should be paralleled with something in the 100pF range. Adjust the slug of each transformer for maximum output. You will have to adjust each transformer if you decide to pick a different station location.
Again, the whistle you hear is most likely due to your transmitter mixing with another signal. The only way to eliminate it is to find a completely dead portion of the dial, or to place your radio closer to the transmitter so that the transmitter overwhelms the distant station that's mixing with it, or you must make your transmitter strong enough that it overwhelms distant stations in the vicinity in any case.....which might not be legal. The reason why you don't usually hear a whistle with commercial broadcast stations is because they are very strong, and broadcast over the weaker ones. They are also nearly perfectly spaced due to regulation, so that they are 10kc apart. Still, you may get a 10kc whistle from two stations that are near eachother. Magnavox frequently made radios with a novel device that tuned out the 10kc whistle. I wish my radios had such a device.
T.
Sounds like the unit needs to be more fully evaluated for its RF power output at the oscillator section and then the amplified output from the 6SA7..currently ignoring…. the addition of YET another RF amp at the end .
The 6SA7 currently has a resistor as its plate load resistor. The degree of RF output from that stage can be enhanced by the utilization of an ~ 2.5 MH RF choke coil in its place. Or even… more if a tuned LC circuit is used in that position, however that might be touchy in the feed back situation back to the oscillator IF precisely tuned right onto frequency.
As per your tuning situation on the reception on two places on your receiver …the frequency spacing seems to be just about what one would expect when receiving images.
You also mentioned the AF input level, and by your reference to a headphone impedance as well as that AF output level, sounds like that might be a bit on the low side..but then, you would be able to tweak it with the volume control.
If you were using a common CD or DVD player with RCA jack AF outputs, you would be expecting in the range of ~500MV----1VAC audio output from one of those units…... but typically no volume adjustment capability.
The use of the isolation transformers should have mostly solved the AC line isolation problem in respect to connection into a computers audio output, but there might be some ground loops and induced hum issues that may have to be ironed out…one would just have to try it and see what occurs.
The temp of the transformers seem to be right in line with the power currently being consumed by them. The most being from the filament string demands on the first transformer, and then but a miniscule amount from the second transformer with it supplying mere B+ requirements.
73's de Edd
I forgot to query as to the actual mass of capacitance that you eventually ended up using for the tuning of the oscillator coil, as it is now schematically shown as 2 capacitors, plus the suggested smaller “vernier / fine tuning “ trimmer. That certainly made me wonder, when you implied that the oscillator stopped functioning with the addition of merely a decade or so of pico farads added by that variable unit.
Also the frequency that you are shooting for is supposedly 1050 or 1400, as per your figures supplied and if we assume that the oscillator coil that you are using is a common BCB oscillator coil, that would mandate its producing an output frequency of ~995Khz in order to receive a station at the 540 Khz low end of the AM dial and ~2195 Khz for tuning in the last station at the 1740 Khz end of the dial.
Soooo typically, the osc capacitors tuning section will be having a minimum capacitive value of ~22 or so pfs of capacitance with some stray capacitance thrown in from its mechanical construction and that of a built in trimmer capacitor being set at its minimum value. In the units other position, of it being fully meshed, that may run up into the ~165 pf value of capacitance.
Taking those figures and computing the companion inductance required for the oscillator coil winding that the pair are going to be resonating at will reveal an ~ 165 uh value of companion coil needed.
Referring to those numbers will be revealing that if you wanted to be operating at that 1050 Khz frequency, you would be needing approximately 140 pf of capacitance…or in punching in some other figures…at 1400 Khz, one would be needing
78 pf or at 1600Khz it requires 60pf or at 1700Khz it requires 53pf.
Now in comparing those numbers, I wonder if that there is any possibility that appreciably more than those referenced capacitive values were used, such that you were then putting out a signal at an appreciably lower frequency, such that the received signal(s) were actually the progressively MUCH weaker 2nd (2x) and 3rd (3x) harmonics ?
PeeEss…A 6J5 WILL Ruhhh Effffff O.K….. as several times it was used all the way up into the Shortwave frequencies by companies when they used in their receiver designs as the separate local oscillator tube function in conjunction with another tube used in a Mixer function.
73's de Edd
Take a 100 uH choke from Radio Shack and parallel it with a small value trimmer capacitor....from say 10-150 pF. Wire in series with antenna.
The capacitors you use between stages are rather small, too, for the AM band. 22 pF is very small, and might make for a rather inefficient transfer. Increase to 50-100 pF.
T.
:There are 2 parallel trimmers outside of the coil can, there is also the trimmer that is built into the coil. 1400 is the real frequency the image was at 1050 and 2.1mhz. what I meant by it stopped working was that the extra capacitace from the wire (about 1cm) and the trimmer it self, caused it to transmit at a frequency that I could not find. The transmitter works fine, but needs a huge (500ft) antenna to transmit across the room. When I added the RF 6j5 I could not get any signal out, Not even on an untuned AM cystal set(Am coil and a diode) . The 4.7k plate resistor is a 5000 ohm, and the 50 pf cap is a mica trimmer. Even when adjusted there is no output. All tubes are shielded except for rectifier. none of the sheilds go to b- including coil sheild. All of the previously mentioned tube I have on hand, so I can use them if needed. Right now the main thing is power output, good volume with a relativly short antenna <30ft
T.
:You don't need to buy that solid state kit. Your tube transmitter will work just fine if you make some modifications to it. I have built several tube transmitters, and have been able to get them to transmit throughout my home, and even into the yard at times.
:
:T.
Also, with those hefty isolation transformers on your transmitter (Radio Shack transformers are true line isolation transformers, with each winding on a separate plastic bobbin), you aren't getting very good ground coupling via the transmitters. That said, you must connect the B- line in your transmitter to ground by some other means. Connect through a .05 MFD cap for safety purposes, though your transmitter is already well isolated....but just in case something else isn't. Connect to a radiator or water pipe.
The shields of all of the metal tubes (pin 1) should be connected to B- for good shielding so that feedback is minimized. Idealy each stage should be shielded from the others to prevent the instabilities that feedback can create.
To reduce the frequency of your transmitter (to bring it down to the broadcast band), increase the capacitance in parallel with the grid winding of the oscillator coil. In radios the tuning capacitor for that section is often upwards of 200 pF. Don't put any paralleling capacitor on the plate coil. That is unnecessary. I see a capacitor in the schematic, and it is incorrect. You could technically tune the plate coil, but since it is a smaller coil, the capacitance would have to be larger than that on the grid coil, and it's unnecessary anyway.
Again, be sure to use coupling capacitors around 100pF between stages. 50pF and smaller is a bit small for standard broadcast frequencies. Passage of such frequencies may be attenuated. Capacitors around 22pF are best left to short wave and FM broadcast frequencies.....unless an original proven circuit specifically calls for such a capacitor.
T.
SHould say....via transformers.
T.
.....Any updates? These tips should make a markable difference.
:I did put the coil ans trimmer in parallel, and this didn'y boost gain, but did eliminate most of the whistle. I also reajusted the coil trimmers to bring the main frequency down to 1700. Grounding the B- did make it louder, can I ground this into the round hole in the ac socket? Even though it is louder it doesnt go farther, It still needs the 500ft antenna to go to the next room. On my little zentih console that I am using for tests, which has a single 25L6, and the volume needs to be 3X higher than standard broadcast. I am going to try to put the RF 6j5 back in, but use a 100pf coupling cap instead of the 22pf.
Regarding the antenna, how are you going about stringing 500 feet? The antenna must run in a straight line. Running an antenna back on itself sends opposing waves into the air, which cancel and make for an inefficient radiator/collector. Run the antenna in a straight line. Then try the loading coil. The antenna should be from 10-50 feet. Longer is usually better.
As for the trimmer in the grid circuit of the oscillator, it is best to use a larger trimmer, since if you add more fixed capacitance, the trimmer has less effect. Adding more capacitance will bring the signal down even lower than 1700KC.
Be sure to try increasing the value of the RF coupling capacitors. They should be a bit larger than 22 pF. Try in the 100 pF region, and go from there.
Connecting to the round hole on an outlet is fine so long as the outlet is wired properly. You can also use the outlet cover screw. Average people may scratch their heads and even freak out, but it isn't dangerous. If you don't use an actual grounding prong, use a stiff wire bent in a U so that it fits snugly, and doesn't wander into other parts of the outlet. Using a 3 wire cord for the transmitter is best. It will always give you a ground connection when one is present.....though I like grounding through my radiator pipes better. There seems to be less interference there.
Finally, if you really want a more powerful transmitter, it would be wise to purchase two RF transformers from AES, along with some 100-250 pF capacitors (two each). If you do so, mention it and I'll tell you how to wire them in. They will give far superior coupling to the RF output tube, since they can be tuned to the exact frequency you desire.
T.
T.
The 500ft spool was aroung 20ft on the ground and the other 480ft on the spool. The trimmer on the coil is a capacitor as it is from a 1940's zenith 5r086. ALso the frequency has been brought down to 1600. A odd contraption is now attached to the antenna, after the choke and cap. there are 2 adjustable coils from an old scrap Tv power supply chassis(2 leads,adjustable core)in series with one another, inseries with the antenna. This seems to eliminate whistle when one core is completly inserted and th eother removed. I have also built a nice oak box, and installed a on/off switch. The plug is now a 3 wire plug with the ground prong going to the B-. I have not tested this yet, I will tomorrow. I will also try to parallel the 22pf cap with a larger one.
:Did we give up on this one??? Until very recently tubes were the choice for transmitters, mostly because of their superior power handling capabilities. Don't think that tubes won't transmit as far as transistors.
:
:T.
:No not yet.
:The 500ft spool was aroung 20ft on the ground and the other 480ft on the spool. The trimmer on the coil is a capacitor as it is from a 1940's zenith 5r086. ALso the frequency has been brought down to 1600. A odd contraption is now attached to the antenna, after the choke and cap. there are 2 adjustable coils from an old scrap Tv power supply chassis(2 leads,adjustable core)in series with one another, inseries with the antenna. This seems to eliminate whistle when one core is completly inserted and th eother removed. I have also built a nice oak box, and installed a on/off switch. The plug is now a 3 wire plug with the ground prong going to the B-. I have not tested this yet, I will tomorrow. I will also try to parallel the 22pf cap with a larger one.
:
:
: :Did we give up on this one??? Until very recently tubes were the choice for transmitters, mostly because of their superior power handling capabilities. Don't think that tubes won't transmit as far as transistors.
::
::T.
minate whistle when one core is completly inserted and th eother removed. I have also built a nice oak box, and installed a on/off switch. The plug is now a 3 wire plug with the ground prong going to the B-. I have not tested this yet, I will tomorrow. I will also try to parallel the 22pf cap with a larger one.
::
::
:: :Did we give up on this one??? Until very recently tubes were the choice for transmitters, mostly because of their superior power handling capabilities. Don't think that tubes won't transmit as far as transistors.
:::
:::T.
:If you don't mind please stop suggesting that xmitter. I already have a Solid state xmitter. I am building the tube one for fun and a learning experience.
:
:
:minate whistle when one core is completly inserted and th eother removed. I have also built a nice oak box, and installed a on/off switch. The plug is now a 3 wire plug with the ground prong going to the B-. I have not tested this yet, I will tomorrow. I will also try to parallel the 22pf cap with a larger one.
:::
:::
::: :Did we give up on this one??? Until very recently tubes were the choice for transmitters, mostly because of their superior power handling capabilities. Don't think that tubes won't transmit as far as transistors.
::::
::::T.
Glad you got the transmitter working well. You can add even more strength to it by following the suggestions I made, but it doesn't seem to be necessary, and would only push your transmitter into the possibility of being illegal.
T.