RE: Four channel tone filter radio    Gallery
View related threads: (in this forum | in all forums)

Logged in as Guest



Users viewing this topic: none
    Search This Thread  
 
Printable Version

All Forums >> RC Airplanes >> Golden Age, Vintage & Antique RC >> RE: Four channel tone filter radio
Page: <<   < prev  1 [2] 3   next >   >>  

Tower Hobbies Get Coupon Codes Brands  
Login
Message << Older Topic   Newer Topic >>
RE: Four channel tone filter radio - 10/30/2012 11:38 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		And the results.

After neutralization (neutrodynisation) of the rf amplifier and adjusting the modulation amplifier it was finally possible to create a modulationdepth of 78 %. at a supply voltage of 12 V, nice solution because it isn't needed to supply the modulation amplifier from the 100 V converter, so real low power modulation.
Neutralization was the key and needed for this type of tube.
78 % is enough for operating the transmitter and maybe is even better instead of 100 %when using a superregen receiver . .
Now I can rearrange the components, complete the wiring and finish the transmitter.

Taurus Flyer

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 26

RE: Four channel tone filter radio - 11/2/2012 12:47 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		So, wiring is finished, only the plug to load the battery have to be installed but I can load without that the first period.
Next step is field testing, the range. For this transmitter it is a choice, power related to capacity and operating time of the battery.
Current is about 250 mA at 12,5 VDC. The battery capacity is 2500 mAh. Tension for the tube is 100 VDC.
It's easy to generate more power, for example higher tension for the tube, 120 VDC. I think the power will be nearly 50 % more in that case, only point is, is it needed? I'll see.
Channels are adjusted for the existing receiver and are checked already.
After the field test there are still some small activities on the list; dummy battery housing, strap, mechanism for the casing backside, painting the housing and maybe some brass shielding inside.

TF

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 27

RE: Four channel tone filter radio - 11/17/2012 4:02 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		Gents,

A short video showing the radiation pattern of a 27 MHz CLC (center loading coil) antenna,
Have attention for the top of the antenna, most radiation far away of disturbing infuences as earth surface, human bodies etc. This antenna is some more efficiënt than the BLC as we later see in 35 MHz transmitters.





When not visible, open this link : http://www.youtube.com/watch?v=61JF8Isy7f0&feature=player_embedded

Right dimensioning and adjustment of the pi filter is needed to create the right radiation pattern.

Taurus Flyer

Hide Signatures

(in reply to Taurus Flyer)
       Post #: 28

RE: Four channel tone filter radio - 11/19/2012 9:30 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		The birth of a new receiver.
R & D is the reason to develop a second receiver.
Most (European?) super regen receivers do use a colpitts oscillator in the first stage of the receiver. Easy construction and a few components.
Disadvantage for me is the limited adjustable range for the optimal radio frequency for such kind of receivers. Each detector is a "special" and most components are individual selected. (Also there is not realy a capacitive tap used for feed back)
So, why not a Hartley, nearly the same, also possible in grounded base just as the colpitts. Feedback of the oscillator is with a tap on the coil. Frequenty adjustment by coil and/or the parallel capacitor.
Extra profit, turndown ratio of these kind of oscillators is about 3:1, so the 27 Mhz receiver also can be tuned for 9 MHz, short wave length 30 meters, with the same coil and an added tuneable capacitor!

After coupling this premature detector of photograph 1 with the original receiver I could observe the functionality of the squelch filter and that was amasing good, I could hear a few SSB radios, and listen to several sw radiostations, Radio Europa, Ukrain stations etc.
I also have an impression of sensitivity and that seems to be all right too. For these stations the normal airplane antenna wire could does the job, 75 cm long hanging down under the work bench in the workshop.

Photograph 2 was the collpits receiver in the beginning with the first squelch filter which was modified later.

So, next step is a pulse generator for the radio tube transmitter, helpfull for the range check. The ontvanger tone filters are tested and alright so with a (one channel) tone pulser in the transmitter I can do the range check without any help. Just walk away with the receiver.
(Tone pulser, 'galloping Chost'?, no I was thinking of telemetry!!) We'll see, no....... w'll hear, short wave.

TF

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 29

RE: Four channel tone filter radio - 11/21/2012 10:17 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		After the battle,

Hartley positioned on the circuit board, after that, some candle wax applied to fix the components and prevent shortcuts as result of engine vibrations.
The circuit board is still the same as I started with, see the last post and look for differerences.
Now the superregen (Hartley) detector, squelch filter and amplitude limiter is of own design. The audio amplifier is the only original part and still has the three AC125 Germanium transistors, just as the tone filters (not on this photograph).
There is no need to modify the audio amplifier, but easely could be replaced by an operational amplifier,...... old school.

TF

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 30

RE: Four channel tone filter radio - 11/23/2012 2:51 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		Gents, for who is interested,

Still not shown in this thread but interesting is the circuit board with the two tone generators and modulation amplifier of the solid state transmitter. see the circuit diagram within the red lines. This board is hide away in the transmitter caseI, but ...... I did find a picture made a few years ago.
I did design and built this transmitter in (about)1966 so these are all Germanium transistors, The OC 76 transistors of the balans modulation amplifier are mounted back to back in the cooling plate.
The AF 118 (rf final stage, in the green square of the circuit diagram), was basically a high voltage transistor, also used in plate deflection amplifiers in Philips Oscilloscopes (PM3230 for example). With these transistors it was possible to use the supply voltage of 13.5 V. This is transformed to 27 V (top Voltage) by the modulation transformer when dual tones wre transmitted at 100 % modulation depth.

TF

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by Taurus Flyer -- 11/24/2012 6:52 AM >

Hide Signatures

(in reply to Taurus Flyer)
       Post #: 31

RE: Four channel tone filter radio - 11/24/2012 11:48 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		while doing some research for sensitivity of the super regen detector I could make some photographs.

The first photograph of the short moments the 27 MHz oscillator of the detector is switched on. I did use this photograph for photoshopping of the other two photographs

Next photograph (2) with antenna signal so each 100 micro second the 27 MHz oscillator is started for a short burst. After that the oscillator is switched off and the voltage is rising. On any moment the oscillator will start again, initiated by a small signal from the antenna or "random?"

The third photograph is made without antenna signal, the oscillator starting on different moments whenever he wants to but always later than "with input signal", the reason of the wellknown noise of these kind of receivers.

The curve of the squelch signal determines the Automatic gain and sensitivity, that's why the oscilloscope is essential to make and tune the detector.

The quench frequency of 100 kHz is very high and can be helpfull to de-modulate tones of high frequency, however, in the Netherlands the limit is 4 kHz and a quench frequency of 40 kHz, is high enough.

TF

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 32

RE: Four channel tone filter radio - 11/25/2012 12:31 AM   
JMP_blackfoot


 

Posts: 146
Score: 100
Joined: 2/18/2005
Last Login: 5/21/2013
From: Galena, OH, USA
Status: offline 		A very good explanation of the super-regen receiver principle is given in the attached article.
Your detector looks good.

Attachments
Click to see the file in new window.Attachment.pdf


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 33

RE: Four channel tone filter radio - 11/25/2012 11:02 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		JMP,

Nice reading when you are interested in theoretical back grounds of superregeneratieve receiver.
More important for us. Old School modeling, is, how to handle practical tuning aspects such as, lowest possible noise and choise of modern components, but also, biassing and feed back adjustment of the, whatever kind of, oscillator or filter system. Less important but not forget, low current consumption and eleminating of spikes,
All these facts were and still are known. and a few are extremely important for simultaneaous operating systems, for example, what squelch discharge curves to realize.

For an electronic engineer (and modeler) the information of the article is too general, most unproved and sometimes misleading as result of mis interpretations.

TF

Hide Signatures

(in reply to JMP_blackfoot)
       Post #: 34

RE: Four channel tone filter radio - 12/30/2012 7:58 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		A new receiver board that fits in my glider.

The fuseage of my glider isn't wide. Both tonefilter boards I can mount back to back but after that there isn't much space for the original receiver board.
This is the main reason to built me a second receiver board, also to compare the old germanium transistors and modern silicium technic. The Super regenerative detector and quench filter stage are both of own design. The amplifier circuit is still the proven original but all values are recalculated for the new transistors. A 2N3819 FET is used in the detector instead of a transistor.


One step I already made many years ago, the SMD technic. Surface Mounted Devices. So no drilling holes.
The photograph I did make to show the transfer stage in the realisation phase. The already functional and tested experimental circuit for 50 % transfered in the SMD on the board.

This board will be built together with the two tonefilter boards to make one compact(?) receiver.
More to come

TF

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 35

RE: Four channel tone filter radio - 12/30/2012 11:24 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		Transfer completed, tested and working.
Have attention , this is SMD 3D technic in optima forma!!
All transistors, second pcb (hand), about 30 years old just as the blue electrolitic capacitors.
Last part of this project that I could finish this year!

TF

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 36

RE: Four channel tone filter radio - 1/1/2013 10:36 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		Final configuration, so a small update.
Important to know for the glider, total weight of all receiver parts, 375 gram.
Second photograph, the receiver board and the tonefilter boards the way these will be fit together.
In front the first receiver board.
TF

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 37

RE: Four channel tone filter radio - 1/10/2013 2:09 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		So. final product.

Ready for the range check.
The receiver seems to be sensitive enough, without a transmitter antenna the range is at least 6 a 8 meters.
The weather is bad so I didn't check it outside yet.

More to come.

TF

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 38

RE: Four channel tone filter radio - 2/1/2013 12:18 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		Latest development for the near future on our field, a new investment in the radio systems, 2.4 related!!!

A single channel superregenerative receiver.
I can use the receiver for control of an escapement or an electric actuator.
The receiver is built as a multi channel receiver, so there can be coupled more tonefilters with the lf amplifier if I want to. I also can connect head phones to use the receiver as monitor receiver during field tests. I did make the receiver also to have a easy useable reference for transmitters and receivers.
There is one low frequency band pass filter on the board to make the receiver tone selective, there are two relay less outputs available. One output is normally high, and low during receiving of the tone, the other is low and high during receiving just like a relay output. This is needed so I also can use one or two electric activators the way compound escapements are controlled. I will modify Tiny servos for that functionality. Normal escapements I can connect with the second output.
All these whistles and bells do have a price, a lot of components,8 transistors and about 57 electronic components!
The weight is low, 135 grams for receiver, a battery pack and one actuator..

And I wrote, 2.4 related!!
Yes, supply voltage is 2.4 VDC
Cees

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 39

RE: Four channel tone filter radio - 2/1/2013 3:45 PM   
LesUyeda



Posts: 2259
Score: 151
Joined: 10/10/2002
Last Login: 5/24/2013
From: San Diego, CA, USA
Status: offline 		Post #15 was very interesting. In the US, I well remember 97.5 v B batteries, but never an even 100 volts. I didn't the available battery chemistry would allow that.

Les

Hide Signatures

(in reply to Taurus Flyer)
       Post #: 40

RE: Four channel tone filter radio - 2/1/2013 6:09 PM   
iflyj3



Posts: 1385
Score: 100
Joined: 5/18/2002
Last Login: 5/23/2013
From: Paris, KY, USA
Status: offline
quote:

ORIGINAL: LesUyeda

Post #15 was very interesting. In the US, I well remember 97.5 v B batteries, but never an even 100 volts. I didn't the available battery chemistry would allow that.

Les

I remember our dry batteries being a multiple of 22.5 volts. 22.5, 45, 67.5, 90 and 135 volts.

_____________________________

Dan Thompson http://sites.google.com/site/ckffinc
MicroPro8000 http://sites.google.com/site/mp8kinfo

Hide Signatures

(in reply to LesUyeda)
       Post #: 41

RE: Four channel tone filter radio - 2/1/2013 6:43 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline
quote:

ORIGINAL: LesUyeda

Post #15 was very interesting. In the US, I well remember 97.5 v B batteries, but never an even 100 volts. I didn't the available battery chemistry would allow that.

Les


Les, the chemistry is all the same, elements in serier connected to have the right tension.
See the picture, taps on the battery so You can make a choice.
The real voltage is an estimation I think, the basic elements all based on 1,5 V each, that's why the voltages 22.5, 45, 67.5, 90 and 135 we often see.

Cees

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to LesUyeda)
       Post #: 42

RE: Four channel tone filter radio - 2/4/2013 2:03 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		The receiver and the refrigirator.

The range check of the relayless receiver wasn't going well.
Signall was lost at a short distance, even inside the house sensitivity seems to be alright. Temperature!

A receiver made for a supply voltage of 2.4 V is more critical for biassing of the several stages, there is less "voltageroom" for the signal. The tonefilter transistor, a Germanium AC125 already did have added a temperature dependent resistor. It still could be the amplifier or the superregenerative detector that had problems so, both connected to a channel of the oscilloscope and in the refrigerator. Some thin wires and the headphone connection still outside to have contact with the patient.

After some time it was clear it is the amplifier, the noise, visible as a wide dash in the upper part of the screen on the photograph 1, was gone, it was a thin dash now. See 2
Only the bursts of the oscillator were still vissible in photograph 2, so still working, see the thin line in top of the screen at position of the verticals of the saw tooth in the lower part.
The saw tooth in the lower part of the screen is the signal of the detector, and the noise of the detector is visible as some thin double images.
Both signals are 0.5 V/div.

Problem can be solved by adding a NTC resistor in the bias circuit of the amplifier.

More to come.

Cees

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by Taurus Flyer -- 2/4/2013 2:24 AM >

Hide Signatures

(in reply to Taurus Flyer)
       Post #: 43

RE: Four channel tone filter radio - 2/6/2013 10:56 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		So the second temperature dependent resistor added, see the yellow circles.
Receiver is working now in the refrigerator and outside.
In the past we often saw ntc resistors in circuit diagrams. Solving of temperature stability problems often is a time consuming activity.

The second picture is of the Graupner Varioton super regenerative receiver, normally used to combine with tonefilters.
Two ntc's, one for the detector (red circle) the other in the audio amplifier.
This receiver has a pre-amplifier for antenna signal. Nowadays a powerfull transmitter and less sensitive receiver is a better combination than a sensitive receiver and low RF power of the transmitter. Of course a antenna preamplifier also makes the receiver more selective.

Cees

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 44

RE: Four channel tone filter radio - 2/10/2013 1:32 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		So, a first simple successful range check has been done, 60 meter, antenna retracted, within urban areas at a local park. Circumstances, 0 degrees C and snow.
The photograph for the archiv.
More to come.

Edit: added the second photograph, "The day after".

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by Taurus Flyer -- 2/10/2013 10:08 AM >

Hide Signatures

(in reply to Taurus Flyer)
       Post #: 45

RE: Four channel tone filter radio - 4/16/2013 10:13 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		An update for the 2.4 VDC relay-less super-regenerative receiver.
The short range is extended to 100 m with retracted antenna, the long range test still to do.
The audio amplifier I changed in a two stage amplifier, both stages a class A transistor amplifier. Result is, less complicated and less components and even the NTC wasn't needed anymore. I fact the "room" to design within the low supply voltage isn't much. For a multi channel filter receiver more audio power is needed for this single channel the two stages is sufficient. Workable supply voltage range is 2.2 VDC to 3 VDC, and that will do.

The ouput stages are completed to connect a electric servo.
For a solenoid or an escapement a single powered output can do the job and for this low supply voltage a germanium transistor is a good choice. To simulate the normally closed contact of a relay output for a electric powered servo, a second output is needed, inverted to the existing. So I added a silicon transistor and another germanium transistor to neutralize the servo.

A trim potentiometer is mounted on top of the receiver to adjust the sensitivity of the tone filter.

UK USA

I never experienced the 400 Hz tone receivers as often used in the UK and USA, even I know these are less complicated and lighter.
In general, after the superregen detector a low pass filter to distinguish the 400 Hz tone from the quence frequency and amplified in a one stage audio amplifier coupled with the DC output stage.

I don't use these receivers because these are strictly single channel, not expandable, so probably best choice for escapements and GG.

In de past my first receiver was configurated as a single channel tone filter receiver and expanded with one more channel, two channel. rudder. After that I completed a new three channel tone filter receiver, two channel rudder and throttle. If needed this receiver could be expanded again because it had an audio amplifier with low impedance output so more filters could be connected.

A video can be seen here and, as normally when there is a photocamera or video camera, Hanna!!

https://www.youtube.com/watch?v=V79h0nCidzs

Cees

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 46

RE: Four channel tone filter radio - 4/19/2013 11:07 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		A plan for an actuator.
The early Simprop Tiny servos did use a 3 lead battery and the electrical motors were designed for 2.4 VDC.
Such a servo can be modified to an 3 position actuator for the 2.4 VDC single channel receiver.
I can use this actuator for rudder control but maybe I need this also for two position throttle (with a serial resistor) to use with the four channel tone filter receiver. Quick blip with one or two of the channels for two position throttle.
One of the options is with use of three slide contacts so first a plan.

More to come.

TF


Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 47

RE: Four channel tone filter radio - 4/20/2013 4:06 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		So, these were the slide contacts, it looked like the receiver wasn't all too happy with these. To suppres the glitches there have to be added capacitors I think but that all was too much in the small servo and wouldn't make the result all too reliable I am afraid,
In the past I used a separate battery pack for receiver and servo's to suppress the glitches of the 2 channel Metz servo, but that's no solution after all research to create my 2.4 VDC receiver.

So micro switch on top.

This isn't compact but better.
Each pulse the rotation is a quart turn and so the position is alternately left, neutral, right, neutral, etc.
To modify this actuater in 2 pulses right and on pulse left there is a second micro switch needed, but that's the future. These are the small things to wish, and that's the fun with modeling, a process of development and learning.

TF.

Attachments
Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 48

RE: Four channel tone filter radio - 4/21/2013 10:35 PM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		Development is still going strong, for who is interested in the electronics of old radio systems.

I need a quick blip circuit for a two position actuator usable for the four channel and the single channel.
The circuit is of own design and based on the single channel in the first place so one tone signal input.
The circuit will be modified to combine with the four channel, two tone signal input, as a kind of key to prevent unwanted actions of the two position actuator.

About 75 % of the circuit is under test and seems to work ok.

This is PIC less, autentic conventional electronics of the pré operational amplifier period.
The circuit is based on two "one shot" monostable multivibrators.
One to create a period after the input pulse within the second pulse will be accepted and the second to create a fixed pulse for the actuator to change position.
Other transistors to trigger the one shots and to have the right output signals, direct and inverted.
The drawing of the circuit is for own use and experimental.
When someone want a detailed description please ask.

TF

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by Taurus Flyer -- 4/21/2013 11:12 PM >

Hide Signatures

(in reply to Taurus Flyer)
       Post #: 49

RE: Four channel tone filter radio - 4/22/2013 1:09 AM   
Taurus Flyer



Posts: 2370
Score: 123
Joined: 1/9/2004
Last Login: 5/24/2013
From: Almelo, NETHERLANDS
Status: offline 		The circuit is working, this is part of the circuit within the red square.
Still to do the "power transistors" for inverted and non inverted output and the final check coupled with the receiver to check the pulse shape.
After that tuning and mounting the components on the circuit board.
TF

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


Hide Signatures

(in reply to Taurus Flyer)
       Post #: 50

Page:   <<   < prev  1 [2] 3   next >   >>  
All Forums >> RC Airplanes >> Golden Age, Vintage & Antique RC >> RE: Four channel tone filter radio
Page: <<   < prev  1 [2] 3   next >   >>  




Jump to:


 
Google 



Search | Marketplace | Event Calendar | Local Clubs | Magazine | Product Ratings | New Products | Discussion Forums

Photo Gallery | Instructor Search | Field|Track|Marina Search

Advertisers | Hobby Vendor Resources | Rate Manufacturers | Sign In/Sign Up

SITE MAP!   : :   FORUM RULES

RC Universe is a service of Internet Brands, Inc. Copyright © 2001-2013.

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America


1.547RCU1