Parts in Mumbai (India)

Does anybody have a Bharat Electronics transistors datasheet/book ?

I want the datasheet for BEL 2N3773.

(I want the BEL datasheet, not a generic 2N3773 datasheet.)

Specifically I want to know how to decode the hfe grade markings and the date code.

I downloaded the BEL Power BJT Databook in .pdf form a few years ago, but couldn't find it online on their website now (it's probably on some non-indexed deep link). I can't attach it here because the full databook is 22 MBytes, and individual datasheets aren't available in .pdf form.

However, from the 2N3773 page in the databook, no information is shown regarding date codes and hfe grades. DC hFE is shown as between 15..60 at Ic=8A and 5 minimum at Ic=16A. No mention of hFE grade markings, but I seem to remember that B or BX is the high hFE bin (maybe closer to the 60 end).

Just as an aside, the specs are not terribly great for an audio-grade power transistor. fT is only 2 MHz, beta is poor, Vceo is just barely OK, etc. Any modern power transistor like 2sc5200 or its TO3P equivalent, the 2sc5198, runs rings around it and costs about half the 2N3773. I would not even think about using the 2N3773 in new applications - its use is largely confined to Ahuja Public Address Amplifiers and some industrial controls these days. Most importantly, although there is a reference to the PNP complement, the 2N6609, in the datasheet for the 2N3773, I don't think that BEL ever manufactured it at all - the datasheet for the BEL 2N3773 may have just been blindly copied/plagiarized from their foreign collaborator like RCA or Mullard/Philips, without anybody bothering to check, validate or edit the datasheet. I don't think they've ever tested and characterized their devices locally.
 
Last edited:
Micrometals T157-2? Check with Jinanica, off S.P.Road, Bangalore. They may not have the exact same diameter or material, but they'll have something close to it.

Sadly Jinanca has become a big shot. No more retail quantities, and no helpful alternative suggestions. 1 "tray" min. qty. He chased me off when I went looking for a ETD 29 last week.

Has anyone had similar experience? Does anyone know of an alternative?

Thanks.
vkj
 
Sadly Jinanca has become a big shot. No more retail quantities, and no helpful alternative suggestions. 1 "tray" min. qty. He chased me off when I went looking for a ETD 29 last week.

Has anyone had similar experience? Does anyone know of an alternative?

He was fairly patient with me, but that was over a year ago. He showed me various toroids from different manufacturers, including Micrometals. I bought a fairly small quantity of T105-6 (?) or similar (the yellow and white toroid often seen in cheap PC SMPSes), and he was happy to oblige for a total billed value of maybe around Rs.100.

Below that value, my sympathies lie with the vendor - it's no longer viable for them to waste their time on retail customers who buy single items. I suggest clubbing a bunch of purchases together to ensure that the billed value runs to a (few) hundred rupees.

You may want to check with some of the transformer-winding outfits for an alternative source of ferrites - they may not stock it, but may know somebody who does. I think Nagpal used to stock ferrites, but his markup tends to be high. Ask at Kelitronix also.
 
He was fairly patient with me, but that was over a year ago. He showed me various toroids from different manufacturers, including Micrometals. I bought a fairly small quantity of T105-6 (?) or similar (the yellow and white toroid often seen in cheap PC SMPSes), and he was happy to oblige for a total billed value of maybe around Rs.100.

Below that value, my sympathies lie with the vendor - it's no longer viable for them to waste their time on retail customers who buy single items. I suggest clubbing a bunch of purchases together to ensure that the billed value runs to a (few) hundred rupees.

You may want to check with some of the transformer-winding outfits for an alternative source of ferrites - they may not stock it, but may know somebody who does. I think Nagpal used to stock ferrites, but his markup tends to be high. Ask at Kelitronix also.

Im guessing that the problem is more to do with having unsold opened trays lying in inventory. There are innumerable sizes and manufacturers.

Where is Nagpal located? Did you mean Keltronics on SP road? If I remember right Hicotronics also used to sell retail.

Thanks,

Vkj
 
Where is Nagpal located? Did you mean Keltronics on SP road? If I remember right Hicotronics also used to sell retail.

Nagpal is a small shop in the row opposite Amar Radio, on S.P.Road itself. Keltronics/Kelitronix is about midway (near an intersection) from the entrance to S.P.Road to hardware/tools area - he has a lot of Radio/TV parts, so he may have a few UI and RM cores.
 
Hi all,
I am not sure if I'm hijacking the thread here or if this has been answered already but here is my query:
Of all types of components related to DIY audio that are difficult to obtain in India, output transformers are the most painful to find.
Anyone know if there are any places in mumbai that sell these? I specifically ask for output transformers because power transformers - even if of slightly inferior quality - are easier to find. I could find power transformers fairly comfortably in the lane opposite to MH highschool in Thane. I imagine lamington road would be equally easy.

Coming back to output transformers, I am basically looking for 2500 ohms PP to 8 ohms impedence matching transformer.

Of the online sources i found the following (Can fellow members also tell me their opinions of these?) :

1. Delta transformers: Delta Transformers Manufacturer, Voltage Transformer Manufacturers, Stabilizers, El core transformers, R core transformers, Toroidal transformers, 3 phase , voltage stablizer, d.c. power supply, chokes and inductors, New Delhi, kirti nagar, India, ww
2. Miracle Transformers: Audio Line Matching Transformers - Audio Line Matching Transformers Manufacturer & Audio Line Matching Transformers Exporter from Bengaluru, India
3. Vritti associates (no info about these guys but they are from mumbai so an added advantage) Electronic Medical Equipments
Thanks in advance for the help.
 
What is this for ? If you want high quality audio for daily listening, then you must buy foreign transformers (Hammond in Canada or Lundahl in Sweden). (There are also Japanese brands but you will probably have to sell your house to buy them.)

I have had some limited interaction with Miracle. I was not impressed. They were either unable to understand the specification or (more likely) not interested in you unless you're ordering hundreds of transformers. You could buy one of their line output transformers and repurpose it as an OPT, but they are built like a cheap mains transformer - terrible quality.

I think you will get better results if you spend 6 months studying design of audio output transformers (very good books are available on the internet, copyright expired.) and then giving detailed instructions to a local transformer winder in Mumbai.