[Milsurplus] TBX-8 Microphone

[Sean Kelly]

James,

First off, are you measuring with a peak reading watt meter? I've been told that the equations to convert from Root Mean Square (AM) and Peak Envelope Power (SSB) are  RMS X 1.41 = PEP and PEP X 0.707 = RMS.

OK, second, the manual sez transmitter power is 9 watts CW and 3 watts AM. The rule I've been told about AM voice sets is that PEP will be four times as much as power with no modulation. So, it seems repairs are in order to decrease the power in this radio by undoing the modifications that made it so powerful.

I don't know for sure, but it might be possible that turning the audio gain up all the way is the actual cause. By outputting a signal that is that powerful, one side effect is the modulation is not understandable.

Here's the manual. I couldn't just find the specs without downloading it.

http://bama.edebris.com/download/military/tbx8man/Navy%20TBX-8%20Instruction%20Book.pdf

I have a meter like this one that I use:

https://www.ebay.com/itm/STOP-L-K-MICRONTA-3-WAY-CB-TESTER-RF-POWER-MODULATION-SWR/193641037320
[https://i.ebayimg.com/images/g/s~0AAOSwnxlfSiUR/s-l400.jpg]<https://www.ebay.com/itm/STOP-L-K-MICRONTA-3-WAY-CB-TESTER-RF-POWER-MODULATION-SWR/193641037320>
****STOP****L@@K****MICRONTA 3 WAY CB TESTER RF POWER- MODULATION-SWR! | eBay<https://www.ebay.com/itm/STOP-L-K-MICRONTA-3-WAY-CB-TESTER-RF-POWER-MODULATION-SWR/193641037320>
USED NICE RARE MICRONTA TESTERS. 3 RANGE POWER / MODULATION / SWR TESTER. CAT NO 21 – 522 MADE FROM RADIO SHACK A TANDY CORP. ALL ITEM'S SOLD ARE CHECKED GONE THROUGH AND LISTED THE WAY THE ITEM'S ARE.
www.ebay.com
Mine works well although the power reading is always less than the radio was specified for, possibly because they all need to be realigned or due to lower power out when using batteries.

Sean
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Subject: Re: [Milsurplus] TBX-8 Microphone

Another TBX-8 question. My TBX-8 dead keys 12 watts and modulates to 18 watts. Should the TBX-8 provide more peak modulated output? Mic volume is turned up to maximum and mic is 150 ohms.
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