If you have one of the early wireless NBN boxes, they are fantastic for killing radio signal. If I need to calibrate a radio I have to shut the wireless NBN off. Love to know how this crap got into the country?

With the HMV at least it takes an external antenna & you can pop down to the rural supplier & get some Electric fence insulators & line taps. etc. & make a nice longwire antenna. Shed here is Metal so the radio bench has external antennas

Link pin is not always required. A method of recombining & coupling using two transistor radio audio transformers, has been emailed. This actually makes a floating isolated output. Being an inductance with resistance, the OP winding requires DC blocking. A coupling transformer can be used to step up voltage. Voltage swing is needed to drive a valve.

Whilst the circuit of the basic transformer type has been sent and is actually quite common in USA. If there is interest I can send it to Brad.

I may have already been posted elsewhere here?

Basically it provides DC isolation between the radio and that which it connect to & that can be a problem where, especially a valve radio, it was never designed with a PU and is perhaps "Back biased". The HMV here is.

A "Push Pull" transformer is not specified. That is likely as it is putting out of phase signal through. We need to wire to combine two in phase signals. So they are only coupling transformers as used in earlier times to provide voltage gain. Insulation is the main limit.

GTC, yes Faraday could have used our house to demonstrate his principle.

Marcc, Haven't noticed the NBN interference, It's only 9 months old so hopefully not subject to that problem.

Good idea using parts for electric fences for an aerial, I hadn't thought of that.

Got your email thanks, I have posted link to a similar circuit below so anyone looking at this thread can see the outcome.

https://antiqueradio.org/iPodAdaptor.htm

These are the output transformers I used from Jaycar (I cut off the centre tap):

https://www.jaycar.com.au/500-ohm-centre-tapped-8-ohm-miniature-output-transformer/p/MM2530

This is a Farm: One does not buy (if you can) stuff to make a longwire that can't out perform the fence stuff for insulation & you can get good line taps. I normally put a soldered connection eye terminal on the down wire as that can be bolted to some of the line taps. I use fencing wire as I normally have rolls of it & its strong. To keep it taught the last insulator has clothesline, through a pulley, with a dead weight on it (sash weight) Electric fence insulators a good for around 10kV.

There are newer NBN boxes that don't do it, but try getting the dodgy one replaced.

Apart from this building being a Faraday cage. I was amused to note that the power company got caught out like that. Many seem to totally not understand radio propagation. As I have related recently, they put the dumb meter, into a new meter & distribution box here. Metal an superbly earthed in an ancient creek bed. New transmitter no antenna. Several months later a person arrives & puts two antennas on it, as its not talking to them, or another meter (none closer than half a mile) ???

I am of the opinion that the transformers should sort it. Others have tested it.