Ever ready radio with A type chassis.

[TrevorG3VLF]

IF Transformers.
I have checked IF transformers by inputing a signal to the primary and looking at the secondary with a scope. Swing the generator frequency and look at where the secondary peaks. It is likely to be a few kHz low because of the scope capacitance.
Then reverse the action to check the primary resonance. All four tuned circuits can be checked in a few minutes and no soldering is involved.
Resistance measurements will not check for the odd shorted turn but a short will kill the resonance.

[davidgem1406]

Hi Lawrence,
I checked the 5214 and the value given is 27R for all 4 windings, the circuit is very similar to the model D that uses the type A chassis.
The DC resistance of the 2 IF's in my chassis are First IF L4 25.1R L5 74.4R, Second IF L10 26.9R and L11 26R.
That could well indicate that the First IF is faulty, I have thought that for some while now but needed to check everything else first.

Hi Peter,
Disconnecting the trimmers should make no difference to the resistance reading. The IF's are still wired into the chassis, so far I have avoided pulling them out. It looks now like the first IF,at least, has to come out.
Yes, I will add a couple of pictures.

It now means that if the resistance reading given for the 5214 is correct for mine, and it looks to be so, then I don't have a substitute IF as the ones I have all have windings between 5.5R and 10R.
Unless the 74R winding has a bad connection on the winding.

Regards,
Dave

[ms660]

Originally Posted by davidgem1406

Connecting the signal generator produced nothing, absolutely nothing, I even tried connecting directly to the IF amplifier valve, but still nothing.

I would investigate that first (the IF amp/detector) given the fact that the IF amp's IFT appears to have the correct winding resistances, connect a resistor in the meg ohm range between g1 and chassis when connecting the signal generator to g1 just in case the 1st IFT's secondary is OC at signal voltage but measuring 75 ohms when subjected to your meters test voltage (it can happen)

Lawrence.

[peter_sol]

I would not worry about the resistance difference just try the spare IF transformer you have and see what happens.It looks like a lovely little set.

[Mike. Watterson]

You need to use 100K source and 10:1 scope probe to check alignment of an IFT out of the set.
In the set it's best to use 10:1 scope only on anodes and feed signal generator via LO tuning cap with that set to MW and minimum frequency (i.e. about 530 KHz.) to avoid detuning. Final adjustment is best with scope or wobbulator input on the input to the volume control. Even the 10:1 probe detunes Valve IFTs slightly, especially the older, larger higher Q types.
There is a reason why a one valve IF is about the same or as four stages of cheap AM transistor radio. Double tuned critical coupled high Q coils (A dual filter rather than transformer) vs a quite low Q single tuned coil that's a close coupled transformer and a low input impedance base vs high input impedance grid. You'd need a combination N-JFet and NPN bipolar to get the equivalent of a late 1930s RF pentode used as an IF amp.

[davidgem1406]

I did check one set of spares I had using the sig gen and a scope, they were OK.
However I will not be needing them now.

I removed the first IF and opened it up for inspection. The problem was there. One of the connecting wires had lost 2 of its strands, there are 3 in all. I believe that is why it read 74R. If each strand were 74R then 3 in parallel would be about 25R.
I managed with a good deal of time and fiddling to get at the point where the break was and managed to eventually with hot iron to get the varnish to lift and solder to take.

Having made a solid joint the winding then came to 25R. I then found some very fine stranded wire that I soldered to the terminal, then bent it so that it curved towards the broken wire and sat right under it. It was quickly soldered and checked again, still 25R.
It was then fixed to the coil former with hot melt glue so that it could not move about.

The IF was reassembled and put back into the chassis and wired.

I then attempted to align both IF's but could get nothing to come through. Twiddling the trimmers in sequence did not help.
I then moved the generator to the grid of V2 and tried that. I found a spot where the signal could be heard faintly. Adjusting the trimers one by one brought it up a step.

The generator was returned to the front end and I was able to peak the 2 trimmers there. I checked and adjusted it all in sequence again.

The link shorting out the oscillator was removed, along with the resistor across the frame aerial.
I was then greeted with a number of radio stations on MW and 1 on LW.

However, on trying to align the RF side that was a failure because I could not pick up the radiated signal from the generator, but I could get radio stations and move them up or down the scale, peak them loud or quiet etc.

Also I found that the station on LW at 1400 was Smooth Radio, they don,t do LW. I could move it up or down the scale with the LW trimmer, strange!

First I will have to check the generator using another radio to find out if a signal is being radiated, if it is then what?

Then do I have a problem with the oscillator coils? is there a fault there or something jumbled up.

Regards,
Dave

[Mike. Watterson]

I use about 6 turns of wire about 6" dia loop on the signal generator to couple to loop or ferrite aerials.

LW: Did you fix the switch wiring?

Good that you are making progress!

[ms660]

So far as I can make out, there's an error in the LW alignment instructions in the Ever Ready 5214 Trader sheet, should be easy enough to spot.

Lawrence.

[davidgem1406]

Hi Lawrence,
I am not using the 5214 information I am using the type A chassis information as this radio uses that circuit.

Hello Mike,
Yes, that is what I am using, I have tried using a Roberts RIC1 and I can't make any sense on that either. I can get a very weak signal at times but nothing that one could work with. I even added more wire to the coil, but no difference.

As far as I am aware the LW switching was corrected, but I will check it again.

Thanks,
Dave.

[peter_sol]

You will get strong MW stations on LW nothing to worry about
I suspect your Signal Generator has low output.

[Mike. Watterson]

At night I get strong MW. I've no radios at all with MW breaktrough on LW.

Most signal generators have to be set close to minimum output to do alignment otherwise AGC affects apparent response.

[davidgem1406]

Hi Peter,
I have never had strong MW stations appearing on LW before, this is a first for me. This station is loud and clear just the same as the MW station.
I thought that as well, but I recently checked the whole generator out as it did have a fault.
However I did check the output today and its fine with a max output of 400mV p to p. Then using the TP1 pad I had 300mV max on 37R, and maybe 2mV on DA. I would have thought that should be enough.

Hi Mike,
I have tried the signal generator at all settings from zero right through to maximum, but seem to get no response from the radio when radiating the signal.

Today I made the radiation coil a bit larger and with 8 turns.
I also thought that I could try external modulation to the generator as that could be varied in frequency and depth, it may not help, but worth a try.

This set does not have the induction coil for an external aerial on the frame. From the look of the tag-board it never did.
I would like to add that, how many turns of wire would it need, 6 to 10 maybe?

Regards,
Dave.

[ms660]

How are you feeding your radiation loop?

Lawrence.

[Mike. Watterson]

There ought to be a loop aerial in the case. That's very odd!
Possibly 15 turns for L2 and maybe 30 turns for L3 and 1 or 2 turns for L1.
It depends on the size.

I can calculate the approximate turns for a given size based on likely inductance from capacitance and frequency, or if I found my Lissen or A, I can measure.

There is no way the set can receive without a loop or and aerial wire (about 20') and earth. I can't believe it has no loops. Though I suppose it's possible to save money, it's not intended as a portable as the Model A is.

You need a "dummy" aerial if there is no loop. That's basically a pair of resistors and isolating capacitor between the signal generator and the Aerial & Earth sockets. If there is not meant to be a loop, it MUST have a pair of sockets. Note that as short as 8' on a curtain rail from the radio will work for MW (poor for LW, but my 1935 HMV does pick up BBC R4 LW, here in the Mid West of Ireland on that), but only if there is also an earth. I feed my TX loop direct from the signal generator, no pad or interface is needed.


The mains earth will be very noisy in the UK. Here in Ireland, the mains earth earth is a 1.2 m to 1.5m spike in the ground near the mains in. The mains in neutral is bonded to that at every meter box. In the UK, it's best to have 1nF 1kV isolation between a radio earth socket and your own earth spike, if the radio chassis is connected to mains earth.

A loop aerial is MASSIVELY less noisy than a wire aerial + earth.

[Mike. Watterson]

C3 peaks the MW loop 1400 kHz and affects LW. It won't peak if L2 is too few or too many turns.
S1 is closed on MW.
Thus C1 only affects the LW, peak at 300 KHz (or near RTE1 252KHz will do). Again if the coil is missing, too few or too many turns it won't peak.

C9 is tuning LO at 1400 KHz, then C13 is LO at 300kHz.

Most sets the coils set the LF end (600KHz and 175KHz usually). Sets with air cored LO coils (or RF coils if there is an external aerial) use a series capacitor to tune:
So C12 is MW 600 KHz trimming, It DOES affect the LW and also the 1400KHz.
C11 and L7 is shorted out on MW. On LW C11 sets the 176.5 KHz.

So do MW first, 1400 & 600 KHz alternately.
Then do LW and do not touch the MW trimmers. Do 300KHz and 176.5 KHz alternately (or if you have no sig gen use BBC R4 198KHz and RTE 252 KHz, a bit trickier).

If it is not supposed to have a loop, but use a wire aerial then Loop coils L2 and L3 are replaced by air cored coils on or near chassis connected to V1 and there MUST be and aerial and earth sockets or screw terminals.

[davidgem1406]

Hi Lawrence,
It is fed via the TP1 pad that is part of the E2 equipment, I have tried all 3 positions.
There is plenty of signal available from the pad.

Hello Mike,
I think you have misunderstood what I was saying.
The frame aerial is there both MW and LW windings.
What I was asking about is the induction winding for an external aerial, as shown on the type A schematic designated L1.
This radio does not have that loop as part of the frame aerial. It looks as though it has never been there right from manufacture although the 2 tags are there they have not been used (never soldered).

What I was wanting to do was to fit that loop winding to the existing frame aerial as per the type A model. It may help in the case of weak signals.

I have the alignment instructions for the type A, that is what I am following.

I checked the switching for the oscillator section and found no problem there.

Attached are the layout drawing for the switch and for the actual schematic diagram as it really is, not just a single contact as shown on the type A schematic.

Regards,
Dave.

[Mike. Watterson]

The L1 loop is one turn on the rear panel on the 5214, A and C/E, thus connections are on the rear panel. The C and C/A don't have the loop. I don't know if the rear panel of the D and G have the loop. It's probably 1 turn and connections on the panel if it did.
Not part of the frame aerial.

My Lissen version of the 5214 is fine on the internal frame aerial.

[Mike. Watterson]

It seems odd that centre is not off. I'd thought every ER/Lissen battery valve set I have with 3 way is centre off.

[ms660]

If you can't get an output by coupling the signal generator to the receiver via your coupling loop try connecting the RF output from the sig gen (not the TP1 pads 10 ohm or dummy output) to g1 of the mixer via a low value capacitor (try 5pF or a gimmick) to check what's in the ball park regarding Osc/RF alignment.

Lawrence.

[davidgem1406]

Hello Mike,
Thanks for that info. The set did not come with a rear panel so I have no way of knowing if it had the L1 loop. I had just assumed it would be part of the frame aerial.

I will check the photos I have of the switch in its original condition, but I am pretty sure the centre was not the off position. I could be wrong.
Switching wise it would make no difference the way it is now.


Hi Lawrence,
I will try that and hope that it works for me.

Regards,
Dave.