About trying to test unreferenced tubes
and including "new" tubes in the Test Data list:
The included tubes in the
Test Data book are relative to american production with native american
codes. European models are not listed, but additions can be made easily
using equivalence tables or conversion sockets on testing equivalent tubes
with different base, creating in this case a new "selectors" code with
letters and numbers that matches the connections of the tube to be tested.
A more complicated job is to create new data for tubes that are not equivalent
or convertible, but also may be tested by approximation using data listed
on tube manuals referring to a similar tube. If this instrument instead
of being a tube tester was a true tube analyzer (BTW there are 'tube analyzers'
that are in fact tube testers with more control and configuration possibilities),
any tube could be directly tested using data from the tube handbook, setting static class A operation
at average voltages, and comparing results versus handbook data. Then, by injecting the average signal voltage, the plate current will vary showing the transconductance of the tested tube; but here we have two screen voltages, one plate voltage and one signal voltage, the only voltage that can be adjusted is the bias.
- European tubes (Mullard-Philips
tube designation) with code equivalent to the american RMA or RETMA tube
designation: Search the american code in an EU-US equivalence table
and locate this code in the "tube type" column
on the TV-7 test data settings page: EL84 = 6BQ5,
EL34 = 6CA7, ECC81 = 12AT7,
ECC82 = 12AU7, ECC83 = 12AX7,
QE06/50 = 807, QE05/40 = 6146,
EF86 = 6CF8 / 6267 = EF806, etc. Easy.
- European tubes (Mullard-Philips
tube designation) with code NOT equivalent to the american RMA or RETMA
tube designation, but similar (different base and small differences in
parameters) to other Mullard-Philips tubes that acts as substitutes.
Much of these tubes can be tested using the data of these in-circuit equivalents
with the aid of a new socket base or a base converter, correcting FILAMENT VOLTAGE if needed,
and creating a new data line in tube test manual; e.g. the Philips Rimlock EF40, equivalent to EF86 / 6CF8 / 6267 / EF806. The rimlock base of the EF40 shows pins 1 and 8 are filaments, GRID is pin 5, PLATE 2, SCREEN 6, CATHODE 7, SUPPRESSOR 4. By using the filaments / socket table of the data page (or using the bias and filaments pdf file at footer), FILAMENT selectors must be positioned B-Y, GRID on 5, thus "BY5", and the rest "2674", BIAS at "28" and range "B" as per 6267 tube data. This involves the use of an additional Rimlock-type socket or an adapter tool. Another option is to use an octal-rimlock adapter to be mounted on the octal socket of the TV-7, 8 pins → to 8 pins, direct.
The new data to be included in the TV-7 Test Data manual by extracting 6267 info from TB-11-6625-274-12.1 will be:
| TUBE |
FILAMENT |
SELECTORS |
BIAS |
SHUNT |
RANGE |
PRESS |
MIN-VALUE |
Notations |
| EF40 |
6.3 |
BY5-2674 |
28 |
--- |
B |
3 |
18 |
Rimlock base |
- Unreferenced tubes but equal or similar in parameters to others that are referenced, e.g. the 6HS6 tube is not mentioned in the TV-7 test data manual, but is mentioned in a late TV-10 manual. TV-10 is very similar to TV-7, TV-10's BIAS has same final voltage of -40 and same divisions, plate test voltage is also 150, test mode is identical, thus TV-10 test data values can be emulated to TV-7 test data values.
The TV-10 test data line for the 6HS6 tube is:
| 6HS6 |
6.3 |
JR3-5672 |
12 |
--- |
D |
3 |
3000 |
Gm numbering |
"JR3" equals "ET1" FILAMENT/GRID selectors on TV-7, remaining selectors are identical, thus the TV-10's Gm minimum value can be easily converted to a TV-7 meter reading using the divisions / Gm table of the data page (3,000 µmhos or 3 mA/V in range D corresponds to a TV-7 reading of 24), or using the pdf file at footer with the in-between reading values.
The new data to be included in the TV-7 Test Data manual will be:
| 6HS6 |
6.3 |
ET1-5672 |
12 |
--- |
D |
3 |
24 |
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- Using tools with additional sockets.
Eico 610A, a socket-adapter tool to test the most modern tubes. This adapter plugs
into the Noval socket (miniature 9 pin) of any tube tester to enable testing
the last generation of tubes: Nuvistor 5 & 7 pin, Compactron, Decal,
Miniature 10 pin, Magnoval and Novar, but this must be done with care knowing
the characteristics of the tube to be tested, and keeping in mind also
voltages and user options of the tube tester to it is connected, the TV-7D/U
in this case. It can be used using the procedures shown above,
but all will be easier if it is used connected to models of Eico
tube testers for which it was designed, of course.
TV-7 does not have an exclusive plug-in adapter for the latest tube types or exclusive European types, it is necessary to adapt plug-ins from other brands/models (like the one above). Using the noval socket (miniature 9-pin), the maximum switch combinations are available for the adapter, and then a specific test method must be designed for "tube X". Not easy, but possible.
Important warning:The MX-949(A)/U socket expansion kit is EXCLUSIVELY for the I-177 Tube Tester (1944); see manuals TM 11-2627 (check 829 and 832 tubes in the tube list), and TB 11-2627-2 (which describes the MX-949/U and contains the list of tubes compatible with it). Therefore, MX-949(A)/U is NOT for use with the TV-7 series of military tube testers, as all the sockets on the MX-949/U are already present on the TV-7, except for socket X1, which is tested on the TV-7 using the E-105 socket adapter (included with the TV-7). Purchasing one of these socket expansion kits for a TV-7 is redundant and pointless.
— I have included this warning because some vendors, and a popular website for collectors, mistakenly claim that the MX-949/U is an expansion kit for the TV-7. There has NEVER BEEN a socket expansion kit for the TV-7, NOR headphones for the TV-7; as they would be unnecessary. The missing sockets on the TV-7 are the exclusive European types, and for the newer tubes: Nuvistor, Compactron, 10-pin Noval, and 9-pin Magnoval/Novar (which are precisely the ones present in the EICO 610A shown above); but adapting the EICO to a TV-7 is subject to your own skill and knowledge of the test system, see the 'test methods' page.
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