JetKing DIY Radio Kits

[reubensm]

What a lovely thread, brings back so many memories. I had a couple of book called Radio Circuits Vol-1 and Vol-2 (had a grey colour cover and was rectangular in shape) published by the Business Promotion Bureau, New Delhi in the 1970s. It had the circuits of almost all the radios (tube and solid state) available in India at the time. Unfortunately both these are lost but if anyone either has these or comes across these with local sellers of old books, please do pick these up and we can digitize these and make the e-version available to our forum members. There are quite a few asking for old tube radio and transistor radio circuits.

On the topic of AM transmitter, when I was in 6th standard (1983) i received a digest called Electronics Projects Vol-1 (published by Electronics For You). It had a single transistor MW transmitter circuit built around a AC125 transistor by Sandeep Bagchi, in the circuit ideas section. The purpose was to add a phono input feature for playing records through tube radios which did not have a phono (or gram) input and transistor radios. If anyone has this circuit from this early EFY digest, please share it (my copy is long lost unfortunately). This MW transmitter worked so well when I built it, we wired it to an outdoor aerial and used to walk around our immediate neighbourbood trying to ascertain how far the signal would reach. Great memories.

Btw, this edition of Electronics Projects Vol-1 also featured a 3-band (MW/SW1/SW2) radio circuit built around the BEL 700 IC.

 

[Subbu68]

What a lovely thread, brings back so many memories. I had a couple of book called Radio Circuits Vol-1 and Vol-2 (had a grey colour cover and was rectangular in shape) published by the Business Promotion Bureau, New Delhi in the 1970s. It had the circuits of almost all the radios (tube and solid state) available in India at the time. Unfortunately both these are lost but if anyone either has these or comes across these with local sellers of old books, please do pick these up and we can digitize these and make the e-version available to our forum members. There are quite a few asking for old tube radio and transistor radio circuits.

On the topic of AM transmitter, when I was in 6th standard (1983) i received a digest called Electronics Projects Vol-1 (published by Electronics For You). It had a single transistor MW transmitter circuit built around a AC125 transistor by Sandeep Bagchi, in the circuit ideas section. The purpose was to add a phono input feature for playing records through tube radios which did not have a phono (or gram) input and transistor radios. If anyone has this circuit from this early EFY digest, please share it (my copy is long lost unfortunately). This MW transmitter worked so well when I built it, we wired it to an outdoor aerial and used to walk around our immediate neighbourbood trying to ascertain how far the signal would reach. Great memories.

Btw, this edition of Electronics Projects Vol-1 also featured a 3-band (MW/SW1/SW2) radio circuit built around the BEL 700 IC.

Let me check my father's house next time when I go. hope we are talking about the same book. He had a longish book with lot of circuits from Bush, Murphy, Nelco etc. in it. Also some miscellaneous like light activated burglar alarm, earthquake alarm etc.

Also got a set of EFYs, Elektor and Science Today (that used to have one electronic project every month). And some kept bound even. Also some BPB books.

Hope white ants have not eaten them. Feel like booking a ticket only to go and search for them.

I had a booklet with BEL 700 IC radio circuit.

 

[reubensm]

Let me check my father's house next time when I go. hope we are talking about the same book. He had a longish book with lot of circuits from Bush, Murphy, Nelco etc. in it. Also some miscellaneous like light activated burglar alarm, earthquake alarm etc.

Also got a set of EFYs, Elektor and Science Today (that used to have one electronic project every month). And some kept bound even. Also some BPB books.

Hope white ants have not eaten them. Feel like booking a ticket only to go and search for them.

I had a booklet with BEL 700 IC radio circuit.

yes it was a longish rectangular book (about 15cm x 30cm) with a dark green cover (my copy was a faded old copy bought by my father from moore market in chennai in the 1970s) and it had all these circuits. What could also be valuable is that this book had a couple of 5 watt amplifier schematics at the end of it, using PT4 and PT6 output transistors, which could be of value to those who are restoring old Indian Philips amplifiers and record players. I had these books kept carefully (another book from Business Promotion Bureau, New Delhi called Amplifier Circuits Vol-1). However once i left home for my travels, these disappeared. Guess they have been sold away with scrap, used newspapers and books, etc. Thanks to FM Greenhorn, I now have a copy of Amplifier Circuits Volume 1 and Volume 2. He managed to find these with a local used book seller.

 

[Subbu68]

Get this if you can

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www.amazon.in

 

[Jolly 7]

Wow! Thanks for sharing the pictures. You must be owning one of the last kits made. Do you have the contact details for OM Electronics. Maybe there is a slight chance that they have one kit remaining still.

Sad if true, for all the vintage radio fans. I have been experimenting with AM transmitter circuits but unfortunately the results have not been great so far. There is something beautiful about the simplicity of old-fashioned AM receivers that future generations of electronics tinkerers will miss out on.

Here is a schematic of a JetKing 3-band kit from the excellent book "Basic Radio and Television" by S.P. Sharma (first edition). How this helps. The HX-108 is a great kit also, but I would love to build a multiband SW MW kit like the JetKing.
View attachment 72255
View attachment 72256

And here are some assorted JetKing print ads from old publications. I am actually on the lookout for any old electronics magazines and books from the '60s, '70s, and '80s. If anybody has any leads, please let me know.

View attachment 72259
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View attachment 72261

Wow! Thanks for sharing the pictures. You must be owning one of the last kits made. Do you have the contact details for OM Electronics. Maybe there is a slight chance that they have one kit remaining still.

Sad if true, for all the vintage radio fans. I have been experimenting with AM transmitter circuits but unfortunately the results have not been great so far. There is something beautiful about the simplicity of old-fashioned AM receivers that future generations of electronics tinkerers will miss out on.

Here is a schematic of a JetKing 3-band kit from the excellent book "Basic Radio and Television" by S.P. Sharma (first edition). How this helps. The HX-108 is a great kit also, but I would love to build a multiband SW MW kit like the JetKing.
View attachment 72255
View attachment 72256

And here are some assorted JetKing print ads from old publications. I am actually on the lookout for any old electronics magazines and books from the '60s, '70s, and '80s. If anybody has any leads, please let me know.

View attachment 72259
View attachment 72260
View attachment 72261
[/QUOTE

Thank you so much for sharing these wonderful radio memories. I never knew that Jetking brought out other radio making kits in addition to Guru.

Your three-band shortwave radio will be difficult to build without the correct coils. I am attaching pictures of some vintage coils from the Indian market from my collection. I believe these could be shortwave oscillator coils for shortwave bands 1, 2 and 3. I am also attaching some pictures of IFTs for building a MW radio. I am not sure if these are widely available anymore in the Indian market. I do not know if the SW coils can be substituted with anything else. However, as far as the MW Jetking Guru set is concerned, the oscillator coil and IFTs could ,in theory, be substituted with ones from a Chinese HX 108-2 kit. If substituted, the new colour code sequence should be red, yellow, white and black respectively.

 

[Jolly 7]

I have to place these radios near the window to catch the distant stations. Also in my house most of the lamps are kept off when not required. so interferences are relatively less.

I am looking at a Dxing antenna https://www.amazon.ae/gp/product/B00BLW627G/ref=ox_sc_act_title_1?smid=A2QUTRSO1ZHRN9&psc=1

Hi. Yes, that's a good MW passive antenna and it can be coupled both directly and inductively to a radio. I have a Tecsun AN-200 myself and it's particularly handy to carry while travelling. It can be used with almost any radio, modern or vintage.

 

[Subbu68]

Hi. Yes, that's a good MW passive antenna and it can be coupled both directly and inductively to a radio. I have a Tecsun AN-200 myself and it's particularly handy to carry while travelling. It can be used with almost any radio, modern or vintage.

Thanks for the feedback.. placed the order and in maybe the last piece on Amazon for now

 

[Jolly 7]

Since you are in the UK, I think you should be able to snag a Elenco kit. There may be others too there?

As far as radio kits are concerned in the UK, there don't appear to any mass-produced ones here at the moment. The Chinese-made HX 108-2 and the more expensive Tecsun 2P3 appear to have been quite popular here. However, there were British-made kits available for assembly in the sixties and seventies. Currently some smaller companies and individuals sell crystal radio kits etc. online e.g.on eBay, but I have not seen any superhet kits for sale. I do have an unnamed British vintage unassembled kit though that I hope to put together in the near future. Elenco is a US company, but I don't know if they ventured into making pocket or desktop radios with cabinets.

 

[santaji]

@Subbu68: Thanks for sharing. I am familiar with the Elenco AM radio kit from the internet but have never seen one for real. Here is the link to the manual for it: https://www.elenco.com/wp-content/uploads/2011/05/AM-550CK_REV-A.pdf
You are fortunate with your location in being able to receive long-distance MW stations in this day and age, with so much electrical interference around from computers, routers, modems, plasma TVs, CFL bulbs etc.

I have to place these radios near the window to catch the distant stations. Also in my house most of the lamps are kept off when not required. so interferences are relatively less.

I am looking at a Dxing antenna https://www.amazon.ae/gp/product/B00BLW627G/ref=ox_sc_act_title_1?smid=A2QUTRSO1ZHRN9&psc=1

I find that in Mumbai, MW and SW signals are very difficult to get. I have tried this type of active loop antenna: https://www.aliexpress.com/item/4000390592952.html
It does make an improvement, especially on SW, but the results are still not great. It is often mentioned online that this is the best affordable solution for MW and SW antenna for those living in apartments.

At my family farmhouse 250km from Mumbai, the MW band is quite active. I can get AIR stations from other states as well on MW. On SW, BBC World Service comes in fairly well. There, a few feet of wire is all you need as a DXing antenna.

On the topic of AM transmitter, when I was in 6th standard (1983) i received a digest called Electronics Projects Vol-1 (published by Electronics For You). It had a single transistor MW transmitter circuit built around a AC125 transistor by Sandeep Bagchi, in the circuit ideas section. The purpose was to add a phono input feature for playing records through tube radios which did not have a phono (or gram) input and transistor radios. If anyone has this circuit from this early EFY digest, please share it (my copy is long lost unfortunately). This MW transmitter worked so well when I built it, we wired it to an outdoor aerial and used to walk around our immediate neighbourbood trying to ascertain how far the signal would reach. Great memories.

Btw, this edition of Electronics Projects Vol-1 also featured a 3-band (MW/SW1/SW2) radio circuit built around the BEL 700 IC.

Wow that amazing that you could get such good range with a single transistor circuit. Here are some transmitter circuits that I have tried:


The first circuit only gave 1-2 meter range, while the second one covered my whole living room. Audio quality was poor in both.

 

[Subbu68]

As far as radio kits are concerned in the UK, there don't appear to any mass-produced ones here at the moment. The Chinese-made HX 108-2 and the more expensive Tecsun 2P3 appear to have been quite popular here. However, there were British-made kits available for assembly in the sixties and seventies. Currently some smaller companies and individuals sell crystal radio kits etc. online e.g.on eBay, but I have not seen any superhet kits for sale. I do have an unnamed British vintage unassembled kit though that I hope to put together in the near future. Elenco is a US company, but I don't know if they ventured into making pocket or desktop radios with cabinets.

Elenco is a bare bone kit. No cabinet and layout is such that is not meant to be in one. It is very good to educate children but also for experimentation by others. I am thinking how to pack my daughter's board in a box. (Photo in earlier post). Not that sensitive too.

Jetkings were quality kits, with solid cabinets that if cared for can last for years.

TECSUN 2P3 seems to be a highly sensitive design with twin coil. I have the similar design from Grundig. Model is S 350. Unfortunately some issue inside and it drifts.

To try tonight - Grundig S350, Sangean ATS 909 and Sony ICF J40

 

[Subbu68]

I find that in Mumbai, MW and SW signals are very difficult to get. I have tried this type of active loop antenna: https://www.aliexpress.com/item/4000390592952.html
It does make an improvement, especially on SW, but the results are still not great. It is often mentioned online that this is the best affordable solution for MW and SW antenna for those living in apartments.

At my family farmhouse 250km from Mumbai, the MW band is quite active. I can get AIR stations from other states as well on MW. On SW, BBC World Service comes in fairly well. There, a few feet of wire is all you need as a DXing antenna.

If you can get a SONY ANLP-1 that can catch a lot more SW stations in an apartment settings. For MW there are some tuned loop designs on the net that you my try out. They take some space though. I have placed order for Tecsun AN200. Waiting for it.

 

[reubensm]

During my childhood we used to live in a home with a large compound with many coconut trees and arecanut trees (betel nut). The olden times, there used to be a practice followed by locals wherein they would climb to the top of a slanting coconut tree and attach a galvanized guy-wire and run it all the way down, and attach it to a point about 5 feet of the ground on an adjacent coconut tree. The idea was to keep the slanting coconut tree, growing as straight up, as possible. This guy-wire was my very first long wire radio aerial. When my brother and I grew a little bigger (middle school), my brother would climb those tall arecanut trees and put up our aerial, this time with insulators, a long wire running from the top of one arecanut tree to another at diagonal ends of our compound with one end coming down the length of the tree, insulated of course. The wire used was discarded telephone cables (Dad was working in DoT, Govt of India and hence we had access to the DoT's scrap yard, which his boss, seeing our interest in radio and electronics, generously gave us permission to roam around and pick up what we wanted). We used this set up for our radio Dxing and listening experiments also for our AM transmitter experiments. The total length of the wire may have been around 25-30 meters and it would have easily been about 30-35 ft high (arecanut trees were quite tall)

It was on this set up that I used to listen to cricket commentary on the BBC, Radio Australia and dad followed the Royal wedding live on BBC in 1981. On another note, many dont remember this but Pocket radios like the Jetking model mentioned here, became very popular in India because of Cricket. During test matches, it was common to see folks walking down the street with a pocket radio held to one ear. Folks used to carry pocket radios to the stadium when they went to watch the game live and we even carried them to school to check the cricket score during breaks between periods. It was very presetgious if one had a japanese pocket radio from Sony or National Panasonic . Philips was the big India player in this market segment.

 

[Subbu68]

During my childhood we used to live in a home with a large compound with many coconut trees and arecanut trees (betel nut). The olden times, there used to be a practice followed by locals wherein they would climb to the top of a slanting coconut tree and attach a galvanized guy-wire and run it all the way down, and attach it to a point about 5 feet of the ground on an adjacent coconut tree. The idea was to keep the slanting coconut tree, growing as straight up, as possible. This guy-wire was my very first long wire radio aerial. When my brother and I grew a little bigger (middle school), my brother would climb those tall arecanut trees and put up our aerial, this time with insulators, a long wire running from the top of one arecanut tree to another at diagonal ends of our compound with one end coming down the length of the tree, insulated of course. The wire used was discarded telephone cables (Dad was working in DoT, Govt of India and hence we had access to the DoT's scrap yard, which his boss, seeing our interest in radio and electronics, generously gave us permission to roam around and pick up what we wanted). We used this set up for our radio Dxing and listening experiments also for our AM transmitter experiments. The total length of the wire may have been around 25-30 meters and it would have easily been about 20-25 ft high (arecanut trees were quite tall)

It was on this set up that I used to listen to cricket commentary on the BBC, Radio Australia and dad followed the Royal wedding live on BBC in 1981. On another note, many dont remember this but Pocket radios like the Jetking model mentioned here, became very popular in India because of Cricket. During test matches, it was common to see folks walking down the street with a pocket radio held to one ear. Folks used to carry pocket radios to the stadium when they went to watch the game live and we even carried them to school to check the cricket score during breaks between periods. It was very presetgious if one had a japanese pocket radio from Sony or National Panasonic . Philips was the big India player in this market segment.

Nostalgia, nostalgia.....

Used to use the metal clothes line as my antenna..then rigged up a supposedly good antenna with no theory but looking like antenna symbol on top of the second floor to catch AIR Trivandrum in Ernakulam crystal clear - a tuning cap, antenna coil and OA79 connected to the aux in of an old valve radio. TVM was never caught on regular radios.

Pocket radios and cricket used to go hand in glove as you wrote . I used to smuggle my Jetking to school.

My friend Rajiv used to flaunt his SONY Headphone radio in the college (for PDC). And George (not sure of name) his SONY multiband digital PLL radio.

 

[Subbu68]

More radios came out of hiding..thanks to this thread ... away from hifi

Surprised to hear 1476 AM radio from Dubai , nearly 160km away. Also AIR at about 900kHz

From left to right

Sangean WR3 Long Range MW, FM, CDP, aux - PLL TUNING

Sangean ATS 909 world receiver MW /FM /LW/SW all bands PLL TUNING

Sony ICF J40 MW, FM, SW1, SW2 classic analogue dial

GRUNDIG S350 real long ranger MW/SW 1, 2, 3/FM Analogue tuning with digital readout

Have to make a tuned loop

 

[Subbu68]

Hi. Yes, that's a good MW passive antenna and it can be coupled both directly and inductively to a radio. I have a Tecsun AN-200 myself and it's particularly handy to carry while travelling. It can be used with almost any radio, modern or vintage.

Cancelled that order for it. Decided to try make one. Not so difficult.

 

[Jolly 7]

Cancelled that order for it. Decided to try make one. Not so difficult.

During my childhood we used to live in a home with a large compound with many coconut trees and arecanut trees (betel nut). The olden times, there used to be a practice followed by locals wherein they would climb to the top of a slanting coconut tree and attach a galvanized guy-wire and run it all the way down, and attach it to a point about 5 feet of the ground on an adjacent coconut tree. The idea was to keep the slanting coconut tree, growing as straight up, as possible. This guy-wire was my very first long wire radio aerial. When my brother and I grew a little bigger (middle school), my brother would climb those tall arecanut trees and put up our aerial, this time with insulators, a long wire running from the top of one arecanut tree to another at diagonal ends of our compound with one end coming down the length of the tree, insulated of course. The wire used was discarded telephone cables (Dad was working in DoT, Govt of India and hence we had access to the DoT's scrap yard, which his boss, seeing our interest in radio and electronics, generously gave us permission to roam around and pick up what we wanted). We used this set up for our radio Dxing and listening experiments also for our AM transmitter experiments. The total length of the wire may have been around 25-30 meters and it would have easily been about 30-35 ft high (arecanut trees were quite tall)

It was on this set up that I used to listen to cricket commentary on the BBC, Radio Australia and dad followed the Royal wedding live on BBC in 1981. On another note, many dont remember this but Pocket radios like the Jetking model mentioned here, became very popular in India because of Cricket. During test matches, it was common to see folks walking down the street with a pocket radio held to one ear. Folks used to carry pocket radios to the stadium when they went to watch the game live and we even carried them to school to check the cricket score during breaks between periods. It was very presetgious if one had a japanese pocket radio from Sony or National Panasonic . Philips was the big India player in this market segment.

Talking of old Indian radio sets, here's one from my collection that might evoke some memories. It's partly broken but might be repairable.

 

[Subbu68]

Talking of old Indian radio sets, here's one from my collection that might evoke some memories. It's partly broken but might be repairable.

I only have a broken Bush Baron 2 band in my father's place. It was a MW-SW affair and had a large speaker from Celestion, rich sound it was. Got it's long ferrite rod with me . This thread is building up an urge to try salvage that radio.

Then a BPL SANYO 2-in-1 from 1991 that I bought.

 

[reubensm]

This is the Philips transistor radio L3X25T/00 made in holland using OC-series transistors, which we used, while growing up. I think my parents were gifted this radio by one of their friends from Singapore. Dad gave it to me as a birthday gift in 1980 and that was the starting point of all our aerial experiments. When I reached college, I won a radio in a contest from Radio DW and this went into storage and later disappeared. I guess it may have been given away or thrown away. I've been on the look out for one, for old time's sake



the radio i won in a contest on Radio DW in 1990



Note: Photos are stock pics

 

[Subbu68]

This is the Philips transistor radio which we used, while growing up. I think my parents were gifted this radio by one of their friends from Singapore. Dad gave it to me as a birthday gift in 1980 and that was the starting point of all our aerial experiments. When I reached college, I won a radio in a contest from Radio DW and this went into storage and later disappeared. I guess it may have been given away or thrown away. I've been on the look out for one, for old time's sake

View attachment 72300View attachment 72301

the radio i won in a contest on Radio DW in 1990

View attachment 72302

Note: Photos are stock pics

Belated congrats

That Siemens I recognize. I have a similar Sony. Photo coming. Need to restore it a bit.

 

[reubensm]

I find that in Mumbai, MW and SW signals are very difficult to get. I have tried this type of active loop antenna: https://www.aliexpress.com/item/4000390592952.html
It does make an improvement, especially on SW, but the results are still not great. It is often mentioned online that this is the best affordable solution for MW and SW antenna for those living in apartments.

At my family farmhouse 250km from Mumbai, the MW band is quite active. I can get AIR stations from other states as well on MW. On SW, BBC World Service comes in fairly well. There, a few feet of wire is all you need as a DXing antenna.




Wow that amazing that you could get such good range with a single transistor circuit. Here are some transmitter circuits that I have tried:
View attachment 72278
View attachment 72279
The first circuit only gave 1-2 meter range, while the second one covered my whole living room. Audio quality was poor in both.

I have attempted to draw out my MW Transmitter circuit from memory, I hope I've got it right as the memory is from about 42 years ago


Edit: I may have used a 10k resistor instead of 2.2k in the diagram, with the 0.01uf capacitor coupled with the base of the transistor, I can't seem to remember this accurately.