RF transformer suppliers

[mdanh2002]

Hi,

I am thinking to build a TV transmitter from the following website

**broken link removed**

I have most parts, except for the transformer T1, which is described as 4.5-MHz IF-can-style RF transformer (the 1F shown on the website is probably a typo). My local electronics shops do not have this.

Does anyone know where I could find one? An obvious answer would be to look in old televisions/radio and salvage one, but de-soldering and identifying may not be easy.

 

[ericgibbs]

hi,
You may find a close match here, retune using a low pf cap.
Xicon Audio & Signal Transformers

 

[mdanh2002]

hi,
You may find a close match here, retune using a low pf cap.
Xicon Audio & Signal Transformers

Hi eric, thanks for the link. Do you also know of a good online tutorial on RF transformer, including identifying and tuning them? I believe it's good to do a bit of study on this topic

 

[ericgibbs]

Hi eric, thanks for the link. Do you also know of a good online tutorial on RF transformer, including identifying and tuning them? I believe it's good to do a bit of study on this topic

hi,
There is a lot of information on all types of transformers on web.

I would Google for: tuned IF transformer winding

 

[JimB]

I am sure this circuit has been discussed in the past here on ETO.

Before you get too excited, you need to realise that this circuit was designed for band 1 VHF, around 40 to 60 Mhz, do you have a TV receiver for such frequencies?
I am not sure what you have in Singapore, I am guessing UHF.
In which case, building this circuit will be a waste of time.

JimB

 

[mdanh2002]

Hi Eric, thanks for the PDF, I will have a look.

Hi Jim, thanks for the info. i found a reference on this circuit previously on ETO at https://www.electro-tech-online.com/threads/rf-transformer.4854/, but not much help from there.

Analog TV is still common here in Singapore with TV stations broadcasting in both VHF and UHF, PAL B/G. My TV set at home can receive both VHF/UHF supporting PAL/NTSC, as is the case for most modern televisions. The only difficulty is tuning and aligning the transmitting frequency on first power on with a modern auto-scan television (most guides I found on the web suggest using a manual tuning television), but I believe I can live with it.

 

[mdanh2002]

Also, do you think the following can be tuned to 4.5 Mhz and used in the circuit

**broken link removed**

The description says it's IF transformer with variable inductor.

 

[JimB]

My TV set at home can receive both VHF/UHF supporting PAL/NTSC,

OK, no problem then.

as is the case for most modern televisions.

In Singapore maybe but not in the UK, VHF TV went away about 30 years ago.

Also, do you think the following can be tuned to 4.5 Mhz and used in the circuit
**broken link removed**

63 Mhz to 4.5Mhz ? are you pulling my wires?
Sorry, but no way!

The 4.5Mhz bit is to provide the sound carrier which is 4.5 (or 5.0 or 5.5 or 6MHz) away from the vision carrier.
So the frequency will depend on the VHF TV standard in Singapore. (Or at least what your TV will support.

JimB

 

[mdanh2002]

Hi Jim, thanks for the detailed answers. I will go and look for other suitable transformers.

 

[ronv]

A junk TV is your best bet. Usually a small metal can with an adjustment in the center. If it's from a TV it will be the right frequency.