ECH4G

I believe the pinout indicated for this tube is incorrect. My Philips tube manual shows filament in pins 1 and 8, not 2 and 7 as it is on the schematic diagram. Can we double check this?

Mario

Hello Mario.

I have look to Braans VADE_MECUM 1952.  Heater on Pin 2 and 7

(Pinning on RMorg. is allright)  Edit: see post 4.

EDIT: on BABANI 3rd Edition 1958/59 Page 103 says. Heater on Pin 2 and 7 Octal Socket

UCH4 ist also correct Heater on 1&8 !

regards Hans

This is interesting, I have two Philips manuals (FAPESA as it was named down here) and they both show the same info. here is a partial scan from page 128 of the FAPESA Miniwatt manual, edited by ARBO in Buenos Aires, 1968.

The other manual was edited in 1957 and has same info. Are we perhaps in the presence of a variant? Or a typo in both manuals? Note that similar tubes like the ECH35, do have filament in 2 and 7 as well as octal base, but this one is different.

Hello to all!

Since the ECH4G was made by Philips, the Philips manuals must be correct. The Braans VADEMECUM is certainly wrong, it is well known to contain many errors.

The ECH4G is fully unknown in Europe, most probably it was only sold in South America. It must have been very rare, because we still have no picture of this tube nor we have just only one radio set fitted with this tube.

The base diagram shown on this Manual FAPESA is the same as of the UCH4, which is most reasonable.

Meanwhile I have exchanged the base diagram, now it must be correct; it's drawn from the UCH4.

Best Regards

Jacob

Hi all,

the answer is not simple. I gave a look in the Data Manual of my AVO VCM MK IV valve meter. For the ECH4G, AVO gives the following switch setting: 128 748 310. This setting means that heater should be connected to pins 2 (value 2 = H-) and 7 (3 stays for H+). Unfortunately AVO does not list the ECH4A. The setting for ECH4 is 023 854 780, or heater to pins 2 and 3.

Usually AVO tables were considered accurate, but what happened for this tube? May be that AVO made confusion between A and G types. Or even that G was just a selection of A and that Fapesa hastily printed its manual, assuming the same pinout of the side contact base. It would be fine if somebody could check the pinout on the data tables of other reliable tube testers.
 

Regards, Emilio

I found a third copy of the Philips manual, same editor, printed in Buenos Aires in 1976 and it also shows the ECH4G with filaments in pins 1 and 8. Note that the ECH21, which has identical properties except for filament current and pinout, also has filament in 1 and 8.

I think it is possible to have an error on the tube manual and since the tube is so rare, it went unnoticed. The only problem is that we have 3 editions spannig over 20 years (1957 to 1976) and it is strange that an error like this was never noticed.

I will keep on researching. I have asked my tube seller and he will see if he has one to sell. This way we can check the filament and also upload a picture.

Mario

The Katalog Èlektronnyh Lamp (Praha 1964) has the ECH4G with socket O37 and otherwise identical data to the ECH4.

Mark

Braans VADEMECUM, BABANI, AVO VCM MK IV valve meter and Katalog Èlektronnyh Lamp can not be considered as being authentic as Philips is. One started with the wrong information, any others did copy.

Mario can you please check in this Philips manuals about more 6.3 V octal tubes with heater on pins 1 & 8 ?

If there is an ECH4G with that heater pinout, there also must or can be, an octal EBL1G, probably as well EF9G, EZ2/3/4G or AZ1G ?

Jacob

Dear all,

There are too many unsolved questions about this code. First of all, nobody has ever seen this tube and it was not used in any known radio. Another point is the availability in the Philips line of equivalent tubes with octal base: both ECH34, dome bulb, and ECH4A, cylindrical bulb. Them both have heater connected to pin 2 and 7.

As in other countries Philips should have left a relevant freedom to its manufacturing facilities in Argentina. Somebody there could have proposed an early variant of ECH4 to better approach American market. The ECH4G, where G stays for dome bulb, may be the preliminary outcome of a design that evolved in the ECH4A and eventually, somewhere around Philips or Mullard, in the ECH34.

I know, this is only a guess, but can explain why nobody has ever seen the ECH4G. And can also explain why, even with so uncertain pinout, through the years nobody has ever complained of the wrong pinout, either with FAPESA or with Braans, AVO and the many others that gave a different pinout. If AVO in the 20th edition of its Data Manual had not changed the pinout, this can only mean that nobody had ever tried to test a single piece of ECH4G.

I would like to know what says the data manual of other top European tube testers, such as the same Mullard. Of course, I will be glad to read that Mario has found one of these tubes and can tell us the right pinout. Mario, a very interesting problem indeed!

Regards, Emilio

My tube seller said he does not have this tube. His stock system shows 1 but the tube is nowhere to be found. He said he will ask other tube sellers as well to see who has one to sell. It is indeed a rare tube!

I know we should only base on facts but one theory I want to verify is that the pin layout is the same as ECH4, which is the predecessor tube. Both tubes share the same pin sequence and this was probably done in order to simplify the construction of adapters and eventual socket replacement once the ECH4 became hard to find.

Lets see if we can find this tube!

Jacob: I am doing some research before answering your question, give me a couple of days.

Mario

Hello all,

I've just remembered that I have an ECH4G, made in Australia.  The heater pins are definitely 2 and 7, I've just applied 6V to them and it lights up.  The ECH4G was used in some Australian radios.  Please refer to the attached copy of a page from the Philips Valve Data Book 4th ed. 1952.

Regards,

Stuart

Attachments

• Philips Valve Data P80 (32 KB)

Hello Stuart,

these are good news ! Thanks a lot !

Since you've tested on a real-live ECH4G, the proof is obvious. This in turn suggests, the ECH4G and the ECH34 seems to be be fully equivalent !

Then the South American Philips / FAPESA manuals must be wrong, apparently the ECH4G was never used there.

Also many thanks for passing the picture of your ECH4G to its page ! This is a big favour us tube / valve collectors !

Meanwhile I have exchanged the base diagram.

Best Regards, Jacob