Can you spot the difference in the dials

[gezza123]

Not sure if this is the right place, can you please move it Mr moderator thank you.

Hi I went to see Factory David today to collect a TAYLOR 67A, what a nice guy he was, I just wished I could have stayed longer and enjoy his hospitality, thank you David.

Now the intention of the purchase was for me to get a modulation transformer and fit it to mine.
When I got home the first thing I did was to open it up and to get out the transformer; but wait I said lets see if it is functioning as it should then I could make a comparison to mine.

After checking I found what David had told me the tuner vanes had come away from there mounts on one side, so I did a quick fix and the Taylor is working fine.
David had put some components in the modulator circuit to try the transformer for me, thank you David.

Now I find that this would be a shame for me to rob it for parts so I will give it a go at repairing it. I have now opened it all up to do some tests, check alignment etc etc. OH; whats going on here then, it is different to my 67a as there are no trimmers on the coils for fine adjustments. OK,OK let me just check the alignment frequencies, ah they are not very accurate so checked the resistors and some are not to specs I will change them again.

Oh,Oh what is wrong here with the dial can (you tell me) it is very confusing if I try to align this 67A with my 67A.
and Must say hello Mr. D.WALSH
gezza123

here are a couple of pictures of both Dials.
PIC 1 MY 67A
PIC 2 NEW 67A
PIC 3 NEW 67A BAND SWITCH

[gezza123]

other pictures of the outputs.

thanks gezza123

[factory]

Good to hear its gone to a good home.
Its seems to be quite common for Taylor to change the design without changing the model number/letter at all.
I can't believe they reversed the dial on some of them. The modulation switch was also fitted upside down, I had to do a bit of modification to get the knob the right way round.
This is the only picture I have of it before cleaning and fault finding, taken by my brother on his phone so the quality is a bit poor.

Here is a picture of the power supply and modulation side before repair, the 100mA circuit breaker had been bypassed by the previous owner, I only noticed it was open circuit after soldering the wires back.

A bracket was made and a fuse holder fitted.
The modulation was also not working at all, a poor connection was eventually found by swapping the two EC91's, it remained working when they were swapped back. This was found after changing the two TCC Visconol capacitors, which both turned out to be leaky on the Megger.

David

[Radio Wrangler]

Ah! Pic 1 is the special version of the 67A done for Eddystone, for aligning EA12s

David

[dave cox]

One of them has been through a worm hole ?

[turretslug]

Perhaps Taylor made oppurtunistic purchases of large batches of suitable value variable capacitors as they came up on the stock clearance market, some going min to max clockwise, some the other way round (Some radio designers thought of scales in metres, others in kHz).

I never understood why the EA12 tuned right to left, it's as if someone forgot the implications of whether the 1st conversion crystal was above or below signal frequency. But I can't believe they would have done that. I guess one gets used to it....

[dave walsh]

Just the sort of thing that would appeal you Gerry on a technical and humorous level. I think it may be an example of what's known as "reverse engineering" I knew that was in there somewhere but it's taken 24 hours to emerge!
Dave W

I'd always wanted an EA12 but [somehow] didn't notice the scale. That would have really put me off in the unlikely event that I'd been able to afford one!

[Radio Wrangler]

THe EA12 has a cam arrangement moving the main tuning capacitorafter the usual eddystone gearbox, in order to linearise the scale, and I think this is what pushed them into tuning backwards. But there must have been another way.

One of the old gang (founders) of the Dunfermline radio society asked me if I would fix one and generally check it over for him. I did so and then it turned out that he was having a clear out and wanted to be sure that it was OK before selling it. I'd always looked at them in shortwave mag and drooled. Alec named a price and I had to spend most of the evening arguing him up to something that would be fair. So I have an EA12 in the collection and I think I know its history. The old gang had been involved in the first EME contact from Scotland, and I think this recaiver was the IF on the end of the 70cm converter. It's original owner also owned a brewery, so he could afford the new price in the 60's.

David

[gezza123]

HI RADIO WRANGLER.
Thank you for the information in post #4 .very interesting.

Thank you turretslug,
You are quite correct, I looked at both tuners and one is as you say backwards never knew they did things like that.

DAVE W,
Thanks for the laugh, but I would have expected from you to be a lot quicker.HA HA.

Here ar some more pictures of my (TAYLOR TRIO) 20mHz, sorry about the scope pic.

Cheers guys all the best.gezza123

[Chaparal]

to avoid confusing

mHz means Millihertz
kHz means Kilohertz
MHz means Megahertz

Peter ;-)

[dave walsh]

Some people would suggest that I normally think backwards Gerry. Given Peter's clarification, I wonder with what "frequency" the "left hand" models were put out? Using one in each hand they would be great for electronic music production [something I don't scoff at] for sort of mixing/hetrodyning in the manner of modern DJ's/"Turntable-ists". Now that term does amuse me!
I wonder if I've got one somewhere? I know a good repairer
Dave W

[Radio Wrangler]

Looking at the traces on the 1742 scope, it can clearly be seen that the voltage from one of the sig gens is going backwards.This must be from the one with the left-handed scale.

One of the guys in the lab at HP had a party piece of putting an amp and a speaker on an HP wien bridge oscillator, firmly grasping the freq knob in one hand and the level knob in the other, and playing 'God save the queen'.

David