UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Test Gear and Workshop Equipment

Notices

Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders.

Reply
 
Thread Tools
Old 18th Mar 2021, 11:12 pm   #21
Dekatron
Octode
 
Dekatron's Avatar
 
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,282
Default Re: AVO 163 amp board ~ transformers

Specs for amplifier transformer as stated in thread above:

----------------------------------------
Amplifier Transformer:

Use Universal Bridge TF 1313, Marconi, for the following measurements.

PRIMARY:

Resistance: 0,2 Ohm +/-20% at 20C, Inductance at 10KHz 99.5uH, Q-factor: 2.4 +/-10%

SECONDARY:

Resistance: 45 Ohm +/-10% at 20C, Inductance at 10 kc/s 99.5mH +/-2%, Q-factor: 14 +/-10%
----------------------------------------
__________________
Martin, Sweden
Dekatron is offline   Reply With Quote
Old 18th Mar 2021, 11:15 pm   #22
Dekatron
Octode
 
Dekatron's Avatar
 
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,282
Default Re: AVO 163 amp board ~ transformers

Specs for Oscillator transformer:

----------------------------------------
Oscillator Transformer:

PRIMARY:

Resistance: 85 Ohm +/-10% at 20C

SECONDARY:

Resistance: 27 Ohm +/-10% at 20C

Voltage test: Apply 1 Volt RMS at 15 kc/s from a suitable oscillator to the primary winding. Measure open circuit secondary voltage. This should be 0.5 Volt RMS +/-5%. Use a Hewlett Packard VTVM model 400H to measure these voltages.

----------------------------------------
__________________
Martin, Sweden
Dekatron is offline   Reply With Quote
Old 19th Mar 2021, 7:31 am   #23
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 17,857
Default Re: AVO 163 amp board ~ transformers

Now that's interesting. It's a 2:1 ratio step-down

I'd have used a step up into a resistive load and a higher impedance amplifier to work as a current transformer and shunt resistor. This would make a low impedance load for the anode because Gm is supposed to be a parameter at fixed anode voltage.

Primary and secondary windings seem to be the same gauge of wire from Martin's photos. So it looks like the primary has twice as many turns as the secondary, it is also wound outside the secondary, increasing its length (and hence resistance) to over double that of the secondary. This is also the reverse of what I'd expected.

No mention of inductance or saturation current level is made. It would be easy to design a transformer that met those specs but which wouldn't work in the actual application. So I think that isn't really a spec, but just some tests to see if a transformer has failed for repair purposes.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now   Reply With Quote
Old 19th Mar 2021, 8:51 am   #24
Dekatron
Octode
 
Dekatron's Avatar
 
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,282
Default Re: AVO 163 amp board ~ transformers

Quote:
Originally Posted by Radio Wrangler View Post

Primary and secondary windings seem to be the same gauge of wire from Martin's photos.
Did some quick measurements with my caliper and it shows 0.15mm wire on the high ohm side and 0.3mm on the low ohm side, the thicker wire is wound closest to the center. (https://www.vintage-radio.net/forum/...1&postcount=10)

Quote:
Originally Posted by Radio Wrangler View Post
No mention of inductance or saturation current level is made. It would be easy to design a transformer that met those specs but which wouldn't work in the actual application. So I think that isn't really a spec, but just some tests to see if a transformer has failed for repair purposes.

David
The information is from documents called "Test specification for oscillator output transformer" and "Test specification for amplifier input transformer" and these were used for checking of manufactured transformers so they adhered to manufacturing specifications.
__________________
Martin, Sweden
Dekatron is offline   Reply With Quote
Old 19th Mar 2021, 8:53 am   #25
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 6,822
Default Re: AVO 163 amp board ~ transformers

Hi David, as you say a strange design.
Are both of these transformers wound on pot cores of the same size?

Ed
Ed_Dinning is offline   Reply With Quote
Old 19th Mar 2021, 9:05 am   #26
Dekatron
Octode
 
Dekatron's Avatar
 
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,282
Default Re: AVO 163 amp board ~ transformers

No, the oscillator output transformer is a small "normal" laminated transformer.
Attached Thumbnails
Click image for larger version

Name:	CIMG5739.jpg
Views:	45
Size:	120.0 KB
ID:	229553  
__________________
Martin, Sweden
Dekatron is offline   Reply With Quote
Old 19th Mar 2021, 9:11 am   #27
Dekatron
Octode
 
Dekatron's Avatar
 
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,282
Default Re: AVO 163 amp board ~ transformers

I've included both schematics for the Oscillator and Amplifier here so you can see how the transformers are used.
Attached Thumbnails
Click image for larger version

Name:	AVO-VCM163_Amplifier.jpg
Views:	47
Size:	40.6 KB
ID:	229554   Click image for larger version

Name:	AVO-VCM163_Oscillator.jpg
Views:	37
Size:	49.8 KB
ID:	229555  
__________________
Martin, Sweden
Dekatron is offline   Reply With Quote
Old 19th Mar 2021, 12:33 pm   #28
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 6,822
Default Re: AVO 163 amp board ~ transformers

Hi Gents, perhaps if HBGOODY can supply his damaged board to us it can be reverse engineered,

Thanks for the info Martin, I'll try and see what the lam size is for the other transformer

Ed
Ed_Dinning is offline   Reply With Quote
Old 19th Mar 2021, 1:28 pm   #29
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 17,857
Default Re: AVO 163 amp board ~ transformers

Have we got something wrong, somewhere? Even the schematic is drawn to make the transformer look like an isolating step-up,

Yet the lower resistance winding having the fewest turns has been described as the secondary in the test document.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now   Reply With Quote
Old 19th Mar 2021, 1:42 pm   #30
Dekatron
Octode
 
Dekatron's Avatar
 
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,282
Default Re: AVO 163 amp board ~ transformers

Looking at the daigrams and reading the texts of the test specifications it seems like they (AVO) have designated the primary side of a transformer as the "input" side and the secondary as the "output" side.

So on the oscillator the primary side is the one connected to the output transistor and it has some 85 Ohm resistance, and on the amplifier the primary side is the one connected to the Anode circuit and it has some 0.2 Ohm resistance.
__________________
Martin, Sweden
Dekatron is offline   Reply With Quote
Old 19th Mar 2021, 2:22 pm   #31
Bazz4CQJ
Dekatron
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 3,323
Default Re: AVO 163 amp board ~ transformers

For what it's worth, here's a picture of the two boards (amp on LHS). Also, a pic of the reverse side showing the "PCB style". They've loaded showing PBC first. I would have taken these have replacing the electrolytics.

B
Attached Thumbnails
Click image for larger version

Name:	P1020395.jpg
Views:	39
Size:	101.9 KB
ID:	229565   Click image for larger version

Name:	P1020408.jpg
Views:	52
Size:	103.5 KB
ID:	229566  
__________________
Data beats opinions most times... that's my opinion, though I have no data on that.
Bazz4CQJ is online now   Reply With Quote
Old 19th Mar 2021, 4:46 pm   #32
David Simpson
Nonode
 
Join Date: Mar 2008
Location: Aberdeen, UK.
Posts: 2,475
Default Re: AVO 163 amp board ~ transformers

The proposed benefactor of all this research seems somewhat reticent to respond to this thread or the "now closed(by RW)" wanted thread. Dekatron & Bazz have kindly posted pictures of decent working boards, and, as Ed has requested, a picture from HPW of his phooked board would be most welcome. 26 components & an old fashioned tinned copper/ paxolin pcb - just how seriously damaged is it to warrant a replacement,(or even, God forbid) another 163 to be acquired as a donor ?
Ed is the foremost transformer repair expert in the UK vintage radio fraternity, so I wouldn't hesitate to consult him if I needed a T/F repaired for any of my AVO equipment. Likewise, if I was less experienced, I wouldn't hesitate to send an AVO VCM off to Mike Barker for a full service/calibration. Both these wise options would cost far far far less than simply acquiring another VCM, then another, on the open market.
There was an old RAF saying - 'A yokes a poke but juck a fantomime', or words to that effect.

Regards, David
David Simpson is offline   Reply With Quote
Old 19th Mar 2021, 5:22 pm   #33
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 17,857
Default Re: AVO 163 amp board ~ transformers

Let's have a look at that amplifier/metering circuit Martin posted a few posts back.

T1 is not just a transformer, it is also a resonator. Job number 1 is to provide isolation from the HT hanging about on the anode of the valve under test. Job number 2 is to filter off mains frequency components because this is an AVO valve tester and the electrode voltages are unsmoothed mains waveforms from tapped transformers. Maybe this is the reason for 15kHz, to get the Gm test signal further away from 50Hz and its harmonics? Job number 3 is to filter off any harmonics of the 15kHz test signal, otherwise valves with lousy harmonic distortion behaviour will score erroneously wrong better Gm figures. Hopefully the Gm test signal is small enough that job 3 is trivial, but job 2 is very important.

R1 is critical, it is the resistor across which the valve anode current is sensed. Accuracy affects results proportionately.

The 1.99uF (unnumbered, but I assume C1) resonates the input (primary by definition) of T1 as a series tank. The slotted tuning slug in T1 allows the tank to be peaked up on the frequency of the oscillator board, so long as it's within a couple of percent.

D3, D4 are clamping diodes to limit the size of transients, eg from people operating range switches, protecting the transistors. Mounted on the underside of the board they look like later additions.

C2 1990pf 2% acts like a minor part of the overall tuning capacitance. ~The primary and secondary of the transformer are so tightly coupled, magnetically, that despite two windings they act as a single resonator, giving a single pole response.

(By contrast, a traditional radio IF transformer has its windings spaced apart to give rather weak coupling. Each is resonated with its own capacitor almost independantly of the other. There are thus two lightly coupled resonators giving a two-pole response which falls off twice as fast as a single-pole response.)

C2 won't work terribly well, because it is working in series with the rather uncertain input impedance of VT1, but it's an attempt to sample off only a small fraction of the power in the resonator.

R2 C3 is an extra well decoupled derivative of the power rail so that less power rail noise gets to the bases of VT1 and VT2 through their bias resistors.

VT1 is just working as an emitter follower to make as high an input impedance as possible so as not to load the resonator. Note that there are no RF stopper resistors applied to this transistor and its collector goes straight to the (decoupled) power rail. The base sees a low Z ar RF through C2 and the stray C of the transformer. Could this be an area which goes silly if a high performance modern transistor is dropped in, replacing the 2N2926?

VT2 is a common-emitter amplifier (we'll come back to what C7 is doing) which drives VT3, another common emitter amplifier with its emitter resistor fully decoupled to get every ounce of gain out of it.

VT3 drives D1 and D2 (their numbering is another clue that D3 D4 were fire-fighting fixes). These drive the meter with a fullwave rectified version of the signal.

Now comes the clever bit. C8 and C9 act as the capacitance across the meter to smooth the signal going to it. They also provide the DC block missing from the path from VT3 collector to the subsequent circuitry. By having two capacitors in series, they also give a centre tap effect for the signal, combined with the diode action, this point reconstructs the full AC current waveform in the output circuit. The meter sees it rectified, but the voltage on R14 which senses the full AC component is there to be fed back through C7 into the emitter of VT2

So the input of VT2 senses the difference between the signal voltage coming from the emitter follower, VT1, and the current actually passing through the meter.

VT2, VT3 are a feedback amplifier with plenty of gain. The feedback loop compensates the diode drops in D1 and D2, it even compensates for meter resistance.

The purpose of C10 is now revealed, it is a compensation capacitor to roll off the loop gain so that it is stable at high frequencies.

So there you are. No rocket scientists were slaughtered in designing this circuit. There are a few omissions by modern standards (we've learned a bit since then) but it's quite clever.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now   Reply With Quote
Old 19th Mar 2021, 6:24 pm   #34
Dekatron
Octode
 
Dekatron's Avatar
 
Join Date: May 2009
Location: Linkoping, Sweden
Posts: 1,282
Default Re: AVO 163 amp board ~ transformers

Thank you for the detailed explanation, way above my level of analyzing capabilities.

A description of an almost identical amplifier and oscillator circuit can be found in the AVO TT/CT/VT-537 instruction manuals, I've included the desription here both as OCR-text below but also as three pictures so you can see the component references in the text.

Now, there are of course some differences, but only small ones - the 10 Ohm measurement resistor and 1.99F tank capacitor are missing as they aren't needed by the transistor tester, nor is there any output transformer on the oscillator as it isn't needed for the same reason. The input transformer is also connected differently, compared to the VCM163, to the emitter of the first PNP transistor - it is connected to the base via the small 1990pF capacitor in the VCM163 (I just checked that on the PCB) however I don't own a 537 so I can't check if that diagram is consistent with the actual design.

One interesting point is that AVO designates the input transformer as a current transformer in the 537 - should it be seen as one in the VCM163 too? It is also missing the trimmer so It isn't adjustable to the frequency like in the VCM163.

One other interesting point is the description of the amplitude regulation of the oscillator with the thermistors, the same design is used in the VCM163 which drive the output transformer.

----- OCR from AVO TT/CT/VT-537 Instruction manual -----

OSCILLATOR CIRCUIT

This is basically a Wien Bridge oscillator, the frequency of oscillation being determined mainly by the series elements R64 and Cl8, together with Cl9 in shunt with the effective parallel combination of R65, R66 and the input impedance of VT8. The predominant resistive factors in the parallel element are R65 and R66.

Transistors VT8 and VT9 form a low gain amplifier with negligible phase shift at the oscillator frequency of lkc/s. Transistor VT10 is an emitter follower to handle the current requirements in the output circuit. Feedback is taken from the junction of resistor R76 and thermistor TH2, the values of these components being chosen such that constancy of output is maintained for any changes other than ambient temperature changes. The operating current through thermistor TH2 is set during manufacture, by adjustment of potentiometer RV8 connected in the emitter circuit of VT8, to give a volt drop across R76 of 400 millivolts r.m.s.

The effect on the amplitude of the oscillator output due to ambient temperature changes is compensated for by the parallel connected components, thermistor TH1 and resistor R77. To ensure the correct degree of compensation the calibration network is designed such that the load on the oscillator is maintained approximately constant at 3.3k ohms.

AMPLIFIER CIRCUIT

Transistor VT11, together with current transformer T3, provide a low impedance input to the amplifier. Thus the impedance presented to the collector of the transistor under test is reduced to a minimum, the ac impedance being approximately one eighth ohm and the dc resistance approximately 60m ohms.

The signal current from the collector of the transistor under test is reduced by the current transformer T3 in the ratio 20:1 and fed into the emitter of VT11 via the coupling capacitor C24. VT11 is a high gain transistor which ensures that almost the entire signal current flows through to the collector load and this is virtually unaffected by temperature.

A voltage is developed at the base of VT12 which is determined by the magnitude of the signal current in the collector of VT11 and the effective ac impedance of VT11 collector circuit. (The effective impedance of the parallel combination R78, R84, R85 is approximately equal to 5k ohms.)

A signal voltage at low impedance is fed from the emitter follower VT12 to the input of the high stability negative feedback amplifier comprising VT13, VT14 and their associated components. The output circuit is arranged such that the ac signal current flowing in VT14 collector is rectified by MR 17 and MR 18. Its mean value is then displayed on an external ammeter which may be connected to terminations 41 and 42.

The feedback resistor R95 in shunt with R91 defines the sensitivity of the amplifier and as this is fairly high, suitable precautions have been taken to eliminate pick-up of spurious signals. Magnetic coupling between the input transformer and any stray magnetic fields is overcome by screening the input transformers with a mu-metal box. The effect of ripple in the power supply feeding the amplifier is reduced to a minimum by the de-coupling arrangements, R82 and C26, R83 and C27 and R87 and C28.

----- OCR from AVO TT/CT/VT-537 Instruction manual -----
Attached Thumbnails
Click image for larger version

Name:	AVO TT537 OSC-AMP-descritpion.jpg
Views:	17
Size:	104.5 KB
ID:	229593   Click image for larger version

Name:	AVO TT537 OSC.jpg
Views:	25
Size:	30.0 KB
ID:	229594   Click image for larger version

Name:	AVO TT537 AMP.jpg
Views:	21
Size:	30.0 KB
ID:	229595  
__________________
Martin, Sweden
Dekatron is offline   Reply With Quote
Old 19th Mar 2021, 7:29 pm   #35
Bazz4CQJ
Dekatron
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 3,323
Default Re: AVO 163 amp board ~ transformers

Quote:
Originally Posted by Radio Wrangler View Post
Let's have a look at that amplifier/metering circuit Martin posted a few posts back.
David
Many thanks for that; way above my pay grade!
__________________
Data beats opinions most times... that's my opinion, though I have no data on that.
Bazz4CQJ is online now   Reply With Quote
Old 19th Mar 2021, 8:30 pm   #36
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 17,857
Default Re: AVO 163 amp board ~ transformers

In the VCM163, that transformer isn't really working as a current transformer. R1 is the shunt resistor converting anode current into voltage, so it's a voltage transformer.

The shunt resistor could have been scaled for the turns ratio squared and stuck on the secondary, and that would have made it a current transformer by the usual definition. But in this case there would be no DC path for the anode current. So that 10 Ohm resistor is where it is for DC continuity to the valve anode, and the resonator capacitor C1 blocks DC to the transformer primary, so there is no DC current in the transformer primary and they don't need to worry about saturation.

As far as analysing that sort of thing, it isn't difficult, it's just a matter of building up a database in your head of circuit configurations and design tricks so that you recognise them when you see them. Learning how to do it deliberately doesn't work. Exposing yourself to circuit design ideas and looking at a lot of stuff allows it to sneak up on you. This way works, and though slow, it's painless. If I can do it, anyone can. Just a matter of time.

In this amplifier, TR2 is interesting. Its base is being moved up and down by the signal which has been buffered by TR1. Its emitter is being moved up and down by the feedback signal extracted from the meter rectifier. The difference in base-emitter voltage of VT2 sets the collector current VT2 will flow and that gets further amplified to drive the meter rectifier.

So the idea of the transistor bridging two voltages and comparing them. Remember the film with Charlton Heston with one foot on the croups of two separate horses attached to two separate chariots? VT2 must have a similar feeling.

This floating transistor comparator is used in the input stage of just about every transistor amplifier which doesn't have a long-tailed pair at its input. It's a snippet of circuit worth knowing so you can spot them and understand them

VT1, the emitter follower is a very standard circuit, another one for the database.

With a circuit and an explanation, you can read through it and pick up a good number of the points made. Have a break, have a beer or whatever and come back the next day and go through it again. You'll pick up things you missed the day before and other things will snap into clarity. I used to read articles several times picking up new layers of understanding each time. I still do when I come across something I can't follow immediately.

Glad to have helped a bit.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now   Reply With Quote
Old 19th Mar 2021, 8:53 pm   #37
Bazz4CQJ
Dekatron
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 3,323
Default Re: AVO 163 amp board ~ transformers

OK, so it's now 2021, if we wanted to build a modern replacement for that amplifier unit, how easy or hard would that be? Do op-amps ride to the rescue? Is the use of the same anode transformer viable? Let's remember the "shorted turns" problem with some of the meters, hopefully that could be accommodated for by having a gain control designed in?

B
__________________
Data beats opinions most times... that's my opinion, though I have no data on that.
Bazz4CQJ is online now   Reply With Quote
Old 19th Mar 2021, 10:14 pm   #38
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 17,857
Default Re: AVO 163 amp board ~ transformers

Eminently do-able. That transformer or something very like it is important for isolation.

As far as recalcitrant meters are concerned, could make it drive a properly hunky 1mA movement and have a cal twiddler with plenty of range.

Can do it with bipolars, opamps, all sorts of things... even valves?

Opamps are so 1970s. Ask any millennial and he'll tell you there ought to be a phone app for doing it!

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now   Reply With Quote
Old 20th Mar 2021, 12:15 am   #39
Bazz4CQJ
Dekatron
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 3,323
Default Re: AVO 163 amp board ~ transformers

I was hoping you'd say that. Over the past couple of years, I've played with;

(a) a very simple 2-transistor Wien oscillator (supplied as a kit with PCB and lamp thermistor for ~3 from China), which operates well at 14.4kHz with a very good sine wave (as judged by eye) and seems to start-up 100% reliably, and...

(b) an AF millivoltmeter using a dual op-amp and good to 20kHz (you helped me solve a meter thwaking tendency)

and at the back of my mind was an update activity of the 163. I'm not saying that either project fully fits the bill here, but I think that they, or something similar, could be built quite nicely on one PCB of the size of the two boards used for the original osc and amp units.

As I've already got an op-amp in there compensating for the Gm meter, it would actually be a tidying up exercise!

If anyone wants to collaborate on such a project, that would be very good!
If Ed could produce new transformers, we could leave the old boards intact.

B
__________________
Data beats opinions most times... that's my opinion, though I have no data on that.

Last edited by Bazz4CQJ; 20th Mar 2021 at 12:24 am.
Bazz4CQJ is online now   Reply With Quote
Old 20th Mar 2021, 12:31 am   #40
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 17,857
Default Re: AVO 163 amp board ~ transformers

Do a couple of regulated high voltage supplies, a low power negative supply and a heater transformer with switched secondaries and you can save thousands on the VCM163 to start with.

Once you start designing things and see the possibilities, where do you stop? The possibilities really are endless. It's like that unravelling a sweater thing, but in reverse.

If doing boards, there is only one caveat: They are only of use to someone with a faulty VCM163, who therefore has boards and although unable to fix them, is capable of swapping them

... edit.... maybe also someone with a dead Gm meter and wants the freedom to fit a lss sensitive movement.

It's not a difficult project and covers a bit of ground. Sourcing some ferrite cores and winding them is not rocket science, needs no special tools or skills and once you've done your first one and got it working, you have a new freedom and the remains of a scary monster lies with your lance skewering it.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 1:41 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.