[Milsurplus] LF oscillator unit in ART-13

[Mike Morrow]

Kenneth wrote:

>What OTHER things must be done to the ART-13 to
>make it operational at MF?

The T-47(*)/ART-13 has *NO* internal PA tank circuit for LF/MF operation below about 2.0 mc.  You'll need an external PA tank/coupler unit.  There are three to choose from:

1.  CU-25/ART-13 - 200 to 600 kc    (medium-sized unit)
2.  CU-26/ART-13 - 500 to 1500 kc  (small unit)
3.  CU-32/ART-13A - 200 to 600 kc, with antenna switching/metering.  This one is about as large as the T-47, and I believe it will also function to 1500 kc.

There is also a CU-24/ART-13 which is just an external bank of three antenna shunt capacitors for MF/HF work, switched in manually by a SA-46/ART-13A knife switch.

The T-47/ART-13 and O-16/ART-13 (200 to 1500 kc), along with the CU-25 and 26, seem to have been mainly naval service gear.  

The T-47A/ART-13 and the O-17/ART-13A (200 to 600 kc), along with the CU-32/ART-13A, seem to have been mainly USAAF/USAF service gear (as the AN/ARC-8).   I believe the USAF also used the CU-25 with a SA-22/ART-13 antenna switch and meter until the CU-32 was available.

If you don't mind its bulk, the CU-32 is the most versatile of the LF/MF external tank units.

>Does the ART-13 manual list these added items?

Yes, though some of the later USAF manuals don't say much about the CU-25 and 26.

Mike / KK5F