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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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26th Feb 2009, 9:39 am | #1 |
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Ekco Eliminator AC18
Can someone tell me how to use this eliminator, what are all the holes for ? What does what and what goes where please. Let's assume its working safely .
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26th Feb 2009, 9:42 am | #2 |
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Re: Ekco Eliminator AC18
It apears to be an HT only supply ie no LT. H, M, L denotes High, Medium and Low voltage. SG denotes screen grid supply.
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26th Feb 2009, 1:21 pm | #3 |
Nonode
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Re: Ekco Eliminator AC18
Filament supply would have been from the trusty accumulator.
I think that this is one of the early ones. We have had a couple of threads about these so it's worth a forum search. Regards,
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Brian |
26th Feb 2009, 2:54 pm | #5 |
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Re: Ekco Eliminator AC18
Thankyou .Yes I have seen the link before . I still need to know what everything does please . Assume i am stupid , wouldnt be far off there ..
The neg hole is presumably neg lead of HT , the pos goes into one of the two voltage marked holes , which should supply stated voltage depended on what is needed .. so How is the plug in bridging plug used please and what are the upper holes used for . |
27th Feb 2009, 5:47 pm | #6 |
Octode
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Re: Ekco Eliminator AC18
Hello,
As has been said this is an HT only unit so you will need an LT accumulator or eliminator and possibly a Grid Bias battery. You really should have Wander Plugs to plug into the holes in the mains unit but you can improvise with something else. You plug the HT negative plug into the "NEG" hole. You have a choice with the HT positive according to the voltage you require. If you want 120/150v then you use the "120/150" hole and the setting of the H M L plug doesn't matter as the supply is taken straight from the transformer. If you want 50/80v then you use the "50/80" hole. This lower voltage is obtained by using a tapped resistor to drop the voltage rather than a tap on the transformer. Because of this the voltage varies with the current taken by the set, so three different tappings on the resistor are available for High, Medium and Low current and these are chosen by the H, M and L positions of the selector plug. A 1-valve set would probably require the L position and a 4-valve set the H position etc. The best thing to do would be to try the L position first and measure the output voltage with the set switched on under load. If the voltage is too low move the selector to the M position and try again and if it is still too low try the H position. You must measure the voltage under load. The two holes at the top with "SG" between them are only for use if your set has a screen-grid (or pentode) valve which needs its own supply (this is usually marked SG or HT2+ on the set) There are two holes marked "H" and "L" for high and low voltage and the easiest thing to do here is to try the plug in each one to see which works better. (The early screen-grid valves tend to need a lower voltage and pentodes a higher voltage.) If your set has only triodes or has a screen-grid supply derived from the HT supply within the set you just ignore the "SG" holes. If the wireless set has not been used recently it is a good idea to check that there is no connection between the HT+ supply and the valve filaments before applying the HT, and or ,to remove the valves and apply the HT and check the voltage on the filament terminals. Yours, Richard |
27th Feb 2009, 6:57 pm | #7 |
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Re: Ekco Eliminator AC18
Richard , Thankyou that makes it much clearer .I have a 20s set that I have run from the HT with a 2 volt cell for LT , but the set is somewhat distorted on the horn speaker , not greatly , but its hard to listn to..so it could be the set or the unit ,and will need further inspection.
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27th Feb 2009, 8:36 pm | #8 |
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Re: Ekco Eliminator AC18
Could be you need a grid bias battery supply if you are getting distortion. As these had a long shelf life - no current is drawn in use - they did not replace them with units like the eliminator you have. Grid bias batteries were usually 9 V tapped at every 1.5 V. Remember that it is a negative voltage that will be needed so the positive end goes to earth. About 4.5 volts is usual unless large output valves are in the set.
Pat G3IKR |
27th Feb 2009, 10:25 pm | #9 |
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Re: Ekco Eliminator AC18
Thanks Pat .Yes there is one , I made up a new one too , but no difference there it seams .
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28th Feb 2009, 6:59 pm | #10 |
Octode
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Re: Ekco Eliminator AC18
Chipp, have you checked the HT voltage under load? It seems to me very likely that the internal rectifiers will have gone high resistance (assuming metal-oxide types, of course).
-Tony |
28th Feb 2009, 10:16 pm | #11 |
Octode
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Re: Ekco Eliminator AC18
Hello,
Horn speakers often do not give a very good quality of sound and it could be faulty so you might want to try it with a more modern speaker. A low impedance moving coil speaker would need a matching transformer. As Aerodyne has suggested it would be worth checking the output voltage and also the current from the eliminator. It is not a very powerful eliminator giving about 12ma-15ma from the 120/150 tapping and about 3ma-6ma from the 50/80 tapping. What kind of set is it and what valves does it use? Yours, Richard |
6th Mar 2009, 11:02 pm | #12 |
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Re: Ekco Eliminator AC18
Hello , just remembered this thread sorry. How do i check the load ? meter settings and what do i look for please .
The set is a version of the Everyman four . Only MW unfortunately though .Its not exactly like the circuit as far as i can see as there is only a vol pot , yet the circuit shows 2 pots . It looks to have been rebuilt recently and as there is new looking wireing .though its all original type componants . I have tried two horns , One was a small metal amplion ,and the other a wooden cabinet amplion slightly larger drive unit , but sounds the same . I had hoped the set would sound better than it does so im asuming something isnt quite right . As i have said i have made a new GB and there is a new 1.5 volt cell wired in somewhere near the earth relating to the coil there . |
7th Mar 2009, 2:59 am | #13 |
Octode
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Re: Ekco Eliminator AC18
Hello,
First with the set switched on measure the voltage between HT+ and HT-. The meter will have to be set to measure at least 150v. Then disconnect the HT+ connection and put the meter between the HT+ terminal and the wire you have disconnected so the HT current is flowing through the meter. The meter should be set on a range which will measure say 25mA or the nearest above. Switch the set on and this should give you the HT current. The Everyman's Four requires 3 separate HT supplies according to the circuit in July 28th, 1926 Wireless World. HT+1 for the first valve, HT+2 for the second valve, and HT+3 for the last two valves. For initial testing it suggests 150v for HT+1 and HT+3 and 90v for HT+2 so you would connect HT+1 and HT+3 to the 120/150 connection on the eliminator and HT+2 to the 50/80 connection and try the H M and L settings to see which works best. If you do have several HT connections then you would have to apply the above measurements to each one. The instructions state " It will not be necessary to experiment with the plate voltages applied to any of the valves, except the detector (HT+2). The best voltage for this valve should be found whilst listening to a weak signal. The voltage is not critical in any way, but different valves require different voltages for best results." Yours, Richard |
7th Mar 2009, 1:03 pm | #14 |
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Re: Ekco Eliminator AC18
Thanks Richard.Sounds complecated . My set has only two wires for HT and two for LT .At least that is how it is now wired .It may not be correct inwhich case its beyond me at the moment ! The set does work though . It may be a simpler version of the set ? it certainly has some of the features of the everyman including the large coils and basic layout.
see pics, taken by earlier owner . It could be a total bodge up of course |
7th Mar 2009, 2:02 pm | #15 |
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Re: Ekco Eliminator AC18
Normally there would be a grid bias supply as well, the round black component with 4 terminals to the right of centre of pic1 looks like the intervalve transformer, are the terminals labelled? They probably would be something be HT+, A or P, G and GB, if so where does the GB wire go to, and the valves, what are their type numbers?
John |
7th Mar 2009, 2:21 pm | #16 |
Octode
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Re: Ekco Eliminator AC18
I should really take more care when I'm reading these posts, I've just gone back and have seen that you do have a GB battery in the set, so please ignore what I said about grid bias supply.
John |
7th Mar 2009, 10:40 pm | #17 |
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Re: Ekco Eliminator AC18
yes has GB , It can be seen in the first pic camoflaged slightly .The left of the two pull switches on the panal is not wired to anything either .Tother is on off
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8th Mar 2009, 7:59 am | #18 |
Octode
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Re: Ekco Eliminator AC18
I'll have another go, if the valves are triodes you won't need a SG supply, perhaps some previous owner, in the absence of a eliminator with the 3 HTs that Richard says is required, has just wired them all together in a bodge up as you suggest.
John |
8th Mar 2009, 1:05 pm | #19 |
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Re: Ekco Eliminator AC18
Thats interesting thanks . Begining to understand slightly .I have a revised everyman four booklet and that def shows , 3 HT conections . I shall have to get someone with a complete brain to have a look I wonder if it has been wire up together . The rubber wander leads are new definately .
one valve is an HL210 another x11 mabe3or 8 but can read the others |
8th Mar 2009, 8:25 pm | #20 |
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Re: Ekco Eliminator AC18
Hi Chipp, in your picture was there a valve mounted through the screening plate?
This could well be an SG valve and possibley has a 5 pin base as well as a TC. The TC is often the screen grid and would need to go to the corect voltage. Ed |