Solid State Modules - 2m Europa

[G3PIJpeter]

This subject has been aired already in this forum, but largely to do with locating the circuit diagram (which I have sourced from mods.dk as suggested).

Does anyone have any hands-on experience of the 2-metre version? I have a very clean example which is now sitting on the bench with its outer clothing removed. The application of 12 volts lights up the heaters nicely (2 x QQVO3-10 plus QQVO6-40A) and the solid state converter has all the right volts in the right places. However, the aerial socket requires 10 mV of 144 MHz signal (millivolts not microvolts) from the dependable TF2008 Marconi signal generator to obtain an audible output on 28 MHz. I have yet to fire up the TX side.

Has anyone out there got one running?

- Peter G3PIJ

[PeterRoberts]

Hi Peter,

I've just obtained one of these (actually a Europa-C) and am having to do a fair amount of rebuilding. So far the receive side is the only bit that I have had working, and it is quite sensitive. I've not measured the sensitivity, but its good enough to receive beacons in France and Scotland from my Surrey QTH with a 6-element yagi (and no mast head amp).

Possibly yours has had the Rx output FET damaged by somebody putting the 'RF in' to the 'RF out' socket? Have you cleaned the Ant relay contacts (if yours has the relay)? Another possibility is a misalignment of the mixer stage in the receive converter, or the 116MHz oscillator is low in output? If you can get the Tx side fired up that would indicate if the 116MHz LO is working.

Good luck,

Peter
G4DJB

[GMB]

Mine was running last time I used it, but that was a while ago.

By the way, it is worth adding a neon lamp to show the -ve bias voltage is OK, because it's not good if it isn't!

[G3PIJpeter]

Originally Posted by PeterRoberts

Possibly yours has had the Rx output FET damaged ...

I am suspecting that the RF amplifier transistor or the mixer are not very happy and shall replace each in turn as a first stab in the dark. My version does not have a built-in antenna relay so that's not part of the problem - I'm just inputting signal from a decent sig gen and calibrated attenuator into the aerial input at the moment. With some 28 MHz output for a very high (100 mV) input at 144, I have been able to peak all the twiddlables. I am using a copy of what looks like the SEM instruction sheets which contain reference to 'Check Points' that are otherwise not identified. There are other checks that involve measuring the voltage of one of the transistor cans and touching a given point to see if the oscillator stops. What documents do you have? I can PM you a copy of mine to check.
- Peter

[PeterRoberts]

Hello Peter,

Yes, we have the same document, the one that is also on Mods.dk.

I've not looked at it in any detail at it as my unit still needs some work to get it to the point where I can look at it as a transverter, and not just the Rx side (which luckily seemed to work fine).

As for the various test points, Point B is mentioned further down under Tx tests as the collector of the oscillator, and I expect this is the same for Rx as well.

I'm not sure of Point A but will have a probe around inside my unit when it is able to be switched on again (currently in bits for rewiring and replacing some duff parts). I would guess that Point B is in the vicinity of the second ZTX310 transistor, possibly the top of the 470-ohm resistor in the emitter circuit, but that is just a guess until I can check.

I would imagine that Point C is somewhere around the 2N3866 amplifier stage. I don't know if anyone else can shed any light on these test points, but I will search for Point A when I next have power to my Europa.

Good luck,

Peter
G4DJB

[PeterRoberts]

Hello Peter,

An update.

Firstly, the "2N3866" stage I mentioned is marked as such in the document we both have but I'm fairly certain it is not a 2N3866, at least in my unit. It is far too small and the heatsink on it makes it impossible to identify at the moment.

The first picture on this website gives a glimpse at what appears to be the "official" Europa schematic and shows the test points.

73,

Peter
G4DJB

[G3PIJpeter]

Originally Posted by PeterRoberts

The first picture on this website gives a glimpse at what appears to be the "official" Europa schematic and shows the test points.

I've done a screengrab of the circuit and magnified it and, so far as I can make out from squinting at the pixels, the following information is included:

Q1 (RF amp) 40822
Q2 (mixer) 40823
Q3 (amp) BSK20
Q4 (buffer) ZTX310
Q5 (oscillator) ZTX310

Test points:
A emitter Q4 0.75V
B collector Q5 illegible
C emitter Q3 0.5V
D source Q1 0.5-1.0V
E source Q2 0.3-0.7V

I hope I have identified the connections to the semiconductors OK. Can you make out what test point B should measure at? I have replaced both of the electrolytics and the semiconductor supply is a healthy value when 12 VAC is applied to the heater connections.

I'm a long way from applying HT and EHT but shall include GMB's earlier suggestion to fit a visual indicator (or interlock to the screen supply) to the bias rail. I'll keep you posted on progress but available time is a bit restricted for the rest of this week.

73 - Peter

[PeterRoberts]

Hi Peter,

Yes, its a bit of a strain, but I agree with most of your data with the only exception would be that I think that Q3 should be a BSX20 (not BSK20).

Also, it appears that Q6 is a PN5964. I imagine that this is the transistor in the bias line to the QQV06-40a.

As for Point B, its illegible to me too. The only other info we have from the other document is that touching Point B with a screwdriver should stop the oscillator.

I've got a new power cable fitted to my Europa now, and need to get the other end terminated for my FT-101. Then when that's checked I can start applying volts and see where that takes me. I also need to make up some RF cables with the Belling Lee connectors on!

73,

Peter

[G3PIJpeter]

Originally Posted by PeterRoberts

I've got a new power cable fitted to my Europa now, and need to get the other end terminated for my FT-101.

Peter -
Thanks for the corrections. I shall be driving my Europa from a TS520S - not quite FT101 vintage but still pretty old. You can just about see the SEM Europa sitting on top of the Frog at http://www.qrz.com - it looks completely standard compared to the other pictures I have seen and does not seem to have been 'got at' or renovated at all apart from my replacing the two electrolytics. As you say, Q6 is in the bias rail - it is fitted against the inside of the back panel, not on the PCB.
Press on!
73 - Peter G3PIJ

[GMB]

There used to be a sort of manual on the web of which I have a copy. I also have a hard-to-read circuit that I did a little work to improve, but not great.

PM your email address if these are of interest.

[G3VKM_Roger]

If its any help, I have a photographed copy (four pages) of the Europa B model on this PC. Somewhere I should also have a folder with notes on conversion to Six and the original Two to Four conversion article from Radio Communication magazine. May have an original manual somewhere too.

73

Roger/G3VKM

[G3PIJpeter]

Originally Posted by G3VKM_Roger

... I have a photographed copy ... of the Europa B model ... also have a folder with notes on conversion to Six and the original Two to Four conversion article from Radio Communication magazine. May have an original manual somewhere too.

When I started this thread, the only resource on the web was the single document via DKmods. We are now gathering all sorts of 'variations on the theme' together in this forum so your docs would be a useful addition. Can you put them up as thumbnails or will it require a direct email?
73 - Peter

[G3VKM_Roger]

I've not mastered the thumbnail method of posting images, Peter. I can send the images I have on disk if you'll PM me an address. Will rummage for the other info.

Roger/G3VKM

[PeterRoberts]

Hello Roger,

I wouldn't mind a copy of the info too. I will PM you my email.

Incidentally, can anyone tell me how long the original power cable for the Europa was/is? I am having to manufacture my own and don't want to make it too long and incur any unwanted additional losses along the cable.

Many thanks,

Peter
G4DJB

PS. Peter - nice shack photos! I used to have a BC348 many years back.

[G3VKM_Roger]

Pix sent direct, Peter. A photo I didn't include from a SK sale I ran last year (when a couple of Europas went for £20!) shows a cable approx 18" long Europa to driver TRX.

73

Roger/G3VKM