JetKing DIY Radio Kits

[Shindvs]

Jetking MW kit was the first PCB soldering experience for me. It cost then Rs.60 I think. Had a dark grey cabinet and bought from Components and Devices in Ernakulam (Cochin). Prior to that the opener of Sri Krishna Radio Company in Ernakulam gave me a manual of Jetking and made me drool over it till my dad got his bonus to buy me one. Dad also had a collection of books by Janakiraman that started with a crystal set and progresses to a 6 transistor radio. I also assembled Jetking's two band radio after some time.

Unfortunately, the urge to tinker around to get better clarity, more stations etc. without understanding the limitations broke them.

You are correct it was price in Mumbai lamington road price in 1977 year of AM radio 6 Transistor i use work for Jetking 1977 year in mahalaxmi AC market building

 

[Jolly 7]

I have assembled both the pocket radio standard PCB and the 2-band L-board PCB during my school days. You are right about the aerial and oscillator coils not mounted on the board. I had these wired directly to the band switch outside the board. This added an element of flexibility as one could change the band switch and aerial/oscillator coil kit and upgrade to a 3-band radio.

View attachment 92963
Image source: https://www.prohithar.com/l-board-pcb-am-radio.html (use the translate option for the english version)

Thank you for sharing. I am also uploading a picture of the top side of my L-board showing the component layout. This particular board is designed to run off 4.5V DC. My board is an older version as it was designed with lockfit transistors in mind e.g. BF194B instead of its successor, the BF494B. Also the diode type is not specified on my board, but I got it to work with an OA79 germanium diode. Other similar germanium diodes should also work.

 

[reubensm]

Thank you for sharing. I am also uploading a picture of the top side of my L-board showing the component layout. This particular board is designed to run off 4.5V DC. My board is an older version as it was designed with lockfit transistors in mind e.g. BF194B instead of its successor, the BF494B. Also the diode type is not specified on my board, but I got it to work with an OA79 germanium diode. Other similar germanium diodes should also work.

quick question, the OP transistors on the PCB are marked as 187 and 188, I recollect using 2 x 128 for my build and later on 2 x 188 on another board which I assembled.

 

[Jolly 7]

quick question, the OP transistors on the PCB are marked as 187 and 188, I recollect using 2 x 128 for my build and later on 2 x 188 on another board which I assembled.

Hi. At the time I constructed the L-board radio circuit, I used two Hitachi 2SB77 transistors and an Indian 'Beco' split phase transformer. I recall purchasing plastic- cased AC187 and 188 but have not tried them so far. I suspect these might be silicon transistors that have been repackaged to substitute the original metal-cased ones. I think two AC128s were used in the Jetking Guru kit.
If I can find any metal 187s or 188s in my parts box, I might attempt to use them and see if the circuit works, of course bearing in mind that this is an NPN/PNP transistor combination.

 

[reubensm]

Hi. At the time I constructed the L-board radio circuit, I used two Hitachi 2SB77 transistors and an Indian 'Beco' split phase transformer. I recall purchasing plastic- cased AC187 and 188 but have not tried them so far. I suspect these might be silicon transistors that have been repackaged to substitute the original metal-cased ones. I think two AC128s were used in the Jetking Guru kit.
If I can find any metal 187s or 188s in my parts box, I might attempt to use them and see if the circuit works, of course bearing in mind that this is an NPN/PNP transistor combination.

I had a few plastic case BEL 187s and BEL 188s and used them in bias stages as replacements for AC127 and AC132 transistors, in old Ahuja solid state amplifiers. They worked very well in these installations.

 

[Subbu68]

I had a few plastic case BEL 187s and BEL 188s and used them in bias stages as replacements for AC127 and AC132 transistors, in old Ahuja solid state amplifiers. They worked very well in these installations.
View attachment 93131

Posting after a hiatus.

And rekindled radio listening too. In the meantime, got a few more radios too. Further attempt now yields no better AM / FM radio now than I have. Tecsuns are more towards SW that is practically dead. So build one and tweak seems an option

Anyone attempted Tecsun 2P3 kit? $33 from eBay. With the twin coil ferrite antenna, it has been highly rated by some reviewers.

 

[Jolly 7]

Welcome back.
The Tecsun 2P3 has been around for a while and sometimes is available for sale without its plastic case. Tecsun is a well-established name in the field of quality multiband radios and loop antennae. l think the 2P3 is different from other kit radios in that in addition to the twin-coil design it also utilises a ceramic resonator that helps improve selectivity.
The only Tecsun product I own is the AN200 loop antenna, which performs pretty well on MW, particularly after dusk.

 

[Subbu68]

Welcome back.
The Tecsun 2P3 has been around for a while and sometimes is available for sale without its plastic case. Tecsun is a well-established name in the field of quality multiband radios and loop antennae. l think the 2P3 is different from other kit radios in that in addition to the twin-coil design it also utilises a ceramic resonator that helps improve selectivity.
The only Tecsun product I own is the AN200 loop antenna, which performs pretty well on MW, particularly after dusk.

Hi Jolly

Two days at a stretch site investigations for a project and saw your reply only now.

I know of Tecsun. I have a Grundig S350 which is Tecsun BCL2000, analog tuned digital readout field radio. Still working well though every few years I have to open and spray the band switch with contact cleaner. This time I sprayed cleaner and after drying up, a contact spray to keep contacts working. Hope it will hold.

I have twin coil ferrite in Grundig S350 and C.Crane EP Pro (that is a DSP). This makes a difference in reception. Current crop of Tecsuns (PL series, S8800 etc) are good for SW and do not shine that much in MW but really want to try 2P3.3 Elenco kits are already on the table

 

[Subbu68]

Inside A Germanium Transistor

The first transistors were point contact devices, not far from the cats-whiskers of early radio receivers. They were fragile and expensive, and their performance was not very high. The transistor w…

hackaday.com

@Jolly 7 @reubensm @dr.partha

 

[reubensm]

I really enjoyed watching this video

 

[reubensm]

Amazing lengths to which folks went in order to operate their own pirate stations, back in the day.

 

[Jolly 7]

I really enjoyed watching this video

So did I. The OA79 detector diode in this vintage kit is the same one that was supplied with the Jetking Guru radio.

 

[Subbu68]

I really enjoyed watching this video

This news from hackaday popped up on my mobile for me too yesterday. Read it but yet to watch it

 

[Subbu68]

So did I. The OA79 detector diode in this vintage kit is the same one that was supplied with the Jetking Guru radio.

Yes, nostalgia... I wish I picked my components box from my father's place and also my old jetking boards (1band and 2 band). Maybe he threw them out a few years before he passed away.