Found this in the basement boneyard of local NBC affiliate. Should have asked the engineer what it was.

Called a MONITRAN TM-30A RCA # MI-26499

Has crystals on turret type channel selector but front controls suggest it might be a modulator ?

I dunno what it iz, either, but me likey the Box its takin' up residence in....

I dunno what it iz, either, but me likey the Box its takin' up residence in....

Notice I also have another of those RCA rack enclosures below it -- removed the Deco red & chrome strips off them to decorate my audio rack (picture)

Very cool. I've been lookin' for a rack to house my BT modulators.

Those "Boxes" are in high demand by the Boatanchor Boys....They can go for silly big money on You-Know-Where. Especially ones like that, w/an opening lid...You can crack it open for ventilation, or leave it open, which makes it look like you're "working" on yr R-390A or SP-600, & know what you're actually doing...GREAT for poseurs like me...

Found this in the basement boneyard of local NBC affiliate. Should have asked the engineer what it was.

Called a MONITRAN TM-30A RCA # MI-26499

Has crystals on turret type channel selector but front controls suggest it might be a modulator ?

If I had to guess from the name, its a modulator ("TRANsmitter") meant as an accessory to a MONoscope indian-head pattern generator. However, I never saw one of these before.

Edit: Or meant as a TRANsmitter to allow use of TVs as MONItors. A MONItor TRANsmitter.

Can't read the labels on the knobs - that would help!

Can't read the labels on the knobs - that would help!

They say Video Level, Audio Level , Channel Selector (2-13), RF Output, Audio 600 ohm/ HiZ, Audio 400~/Ext, Carrier On/Off.

They say Video Level, Audio Level , Channel Selector (2-13), RF Output, Audio 600 ohm/ HiZ, Audio 400~/Ext, Carrier On/Off.

Sure sounds like my second guess

Sure sounds like my second guess

Yes it sure does - an unusual name but it must mean MONItor TRANsmitter like you said. Will have to get it running - uses PL coax connectors at back.

RCA used the MI prefix for a lot of commercial items, for example sound equipment like the crossover networks used in the public address system for the 1964-65 New York World's Fair. I would like to know what MI stands for. The prefixes of their other products were usually decipherable, like "CTC" - "Color Television Chassis."

Edit - Could it be "Military-Industrial?"

After some searching, found this page indicating that "MI" stood for "Master Item" number.
http://uv201.com/Microphone_Pages/rca_junior.htm

Edit:

Here's an RCA spec sheet that spells out the term:
http://www.oswaldsmillaudio.com/images/rca%20museum%20pics/archive%20pdf's/dec07/MI12484.pdf

2nd edit: and an RCA broadcast equipment catalog in which everything is listed by MI number:
http://www.davidgleason.com/Archive%20Miscellaneous/RCA%20Catalog%201962.pdf

...about 30 years ago. There should be a little RCA emblem above the pilot lamp. I still have the emblem mine came with. I honestly don't remember what happened to the machine. I probably traded it to someone for some other super-cool toy. I used to do that a lot. Occasionally I think about it and wish I had it back. :sigh:

It is a modulator, and if I remember correctly it did B&W only, no color

It was crystal controlled for each channel. PL259s for everything on the back. I can't say it was the exact same model as that one, but it sure looked a lot like it. I may have a snapshot of mine somewhere. I guess I'll need to dig for it.

. There should be a little RCA emblem above the pilot lamp. .... it did B&W only, no color




Yes , I took the emblem off mine and added it to my 1940 RCA tube amplifiers (foto) along with the Deco chrome red pinstripe trims.

I sold the amplifiers with these RCA badges still on (mistake) but still have the decorative strips on my audio rack (previous post foto).

I would be interested in buying that emblem to restore this piece if you have no further use for it.

I'll have to re-cap this unit and fire it up and see if I can get it to pass color ?