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), also 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.
— However, it appears that Hickok had a MIL-adapter for these newly designed tubes. The test data supplement TO 33AA21-5-31M refers to a mysterious "Hickok adapter model 1704" (see the TO 33AA21-5-31M list below), but there is no clear evidence of its existence. In contrast, adapters do exist for Hickok's commercial tube testers: the CA-4 model, which connects to the Octal socket, and the more modern CA-5, which connects to the Noval socket. These adapters must include the appropriate list for each tube tester model, so the TO 33AA21-5-31M list would be the one dedicated to TV-7, but as TO 33AA21-5-31M refers only to "model 1704" it is unclear whether the adapters for commercial tube testers are compatible with military tube testers.
TO 33AA21-5-31M, 1 May 1973. Additional test data for newly designed tubes.
Supplement test data for TB 11-6625-274-12-1 and TO 33AA21-5-31 (Army/Air Force, 17 Jan 1962).
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| See above the TO 33AA21-5-31M list (scroll it down). This test data supplement includes new tubes (1960 onwards) and those of new design associated with new sockets. Some tubes test directly in the TV-7, others require the mysterious "Hickok adapter model 1704". |
Design and operation of a tube adapter by means of a simple example.
Adapting Compactron tube test to the TV-7 is simpler than it seems, since most Compactrons are simply common tube units grouped in a single container. Compactrons can be replaced with individual units of these tubes, provided there is sufficient space on the chassis surface; therefore, this type of replacement will be impossible on a printed circuit board.
- Everyone knows the 6C4 tube (Miniature, EC90).
- Would you like to have two tubes like these in a single unit? That's what the 12AU7 (Noval, ECC82) tube is for.
- Would you like to have three 6C4-type tubes in a single unit? That's what the newly designed 6AV11 Compactron tube is for.
- 6C4 and 12AU7 tubes can be tested with TV-7, but 6AV11 cannot.
— Let's try to design an adapter to test the 6AV11 tube. We need a box, a 6AV11 tube socket, a 3-position switch, and a 5-wire cable.
- In the 5-wire cable, 2 wires are for the filament and the remaining three are for the plate, cathode, and control grid. This cable will allow the TV-7 to be connected to the box.
- The 6AV11 socket with the 3-position switch will be installed in the box. This switch will allow testing of all three sections of the 6AV11.
- TV-7 is set up to test a 6C4 tube (Miniature socket output) or to test a single section of a 12AU7 tube (Noval socket output), but the TV-7's filament switch will be set to 6.3 position and not to the 12.6 position.
- The wires that provide the filament voltage connect to the filament pins of socket 6AV11 on the box.
- The wires from the plate, control grid, and cathode connect to the three input connectors (distributors) of the switch in the box.
- Each of those three input wires has three output positions. Each group of 3 plate wires connects to the 3 plate terminals of the Compactron 6AV11 socket, as do the 3 control grid wires to the 3 control grid terminals, and the 3 cathode wires to the 3 cathode terminals.
- Each switch position will allow testing each triode (6C4, 12AU7) unit of the Compactron; the test parameters and values will be the same as the test on the TV-7.
→ Now we can test 6AV11 with TV-7, and not only that, but ALSO all Compactrons that are a set of 3 triodes.
— Do you need more "rare" sockets? Grab the EICO 610A and connect the TV-7's Noval socket to the EICO 610A input; that way you can test all the unusual triode tubes in its sockets (that's why I bought it). It is important to note that in this case we lose the reference to the test conditions, unless the "rare" tubes are very similar to the standard ones.
Some direct equivalencies of Compactron tubes with standard tube units:
- 6AV11 = 3 x 6C4 (or 3 x half 12AU7).
- 6C10 = 3 x 6AV6 triode only (or 3 x half 12AX7).
- 6D10 = 3 x half 12AT7.
- 6K11 = full 12AX7 + half 12AU7.
- 6J11 = 2 x 6EW6.
- 6AR11 = 2 x 6GM6.
- 6AL11 = 6DT6 + 6AQ5.
- 6M11 = full 12AT7 + 6EW6.
- 6G11 = 6DT6 + 6CU5.
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