Next microphone in this blog will be another HAM INTERNATIONAL microphone. The BIG PUNCHER to name it. This microphone was manufactured in the 80’s and after by Altai of Japan. Mine come from the bay and is really scarce. It was sold under several brand and model names.
So you can find it under:

Leson DT-251.
Ham-master 4500.

Mine was sold by Ham International, a Belgian based company sitted in Gent.


The BIG PUNCHER is a base station dynamic microphone with amplifier and speech compression. Compression is not adjustable and should be around 22dB.

“Nutrition facts”
Year : 1980
Type of microphone : Dynamic
Microphone characteristic : omni directional
Sensitivity : Not given
Nominal output : Not given
Measured output : 10mV (original status)
Measured output : 40mV (modified status)
Max output : 77mV @ 110dBSPL (before distorsion, modified status)
Output at mid Range : 5mV (volume position 3)
Output impedance : Not given
Measured output impedance : 10Kohm
Frequency response : Not given
Amplifier voltage gain : Not given
Compression : 22dB (not adjustable), given.
Meter : Yes
Echo : No
Lock switch : Yes
Tx LED : No
Battery : 9V
Battery test : Yes
External power supply : 12V

Remarks, Measurement have been made at 94dBSPL unless noted (at 1KHz and 600Ohm load) using a fresh 9V battery. All test were made using 9V and not the external 12V input. In the original stand, I found the output voltage to be very low, about 10mV so I take away the last resitance in the audio chain ( the one with the black point on the right on the picture below) and got 40mV which was sufficient in my case. I also own the Leson DT-451 and the output voltage meet the BIG PUNCHER value. All transistors in the amplification have been tested and found to be in good shape… Not really a BIG PUNCHER.



Listen to the sound of the HAM INTERNATIONAL BIG PUNCHER, tone 1 volume 3.

Listen to the sound of the HAM INTERNATIONAL BIG PUNCHER, tone 3 volume 3

Listen to the sound of the HAM INTERNATIONAL BIG PUNCHER, tone 6 volume 3

Below, the BIG PUNCHER with his brother, the LESON DT-251

My opinion : silent TX pedal switch, full metal jacket, compression is good but out

put level could have been much bigger. Very strange tonal control which completely  cut high tones at low position and completely cut low tones at high position. At mid range , both high and low are present but at a very low level… I think the BIG PUNCHER or the LESON DT-251 were the ALTAI response to the TURNER EXPANDER 500 (the original one) BIG is beautifull but the result is disapointing (with both my exemplar).

My rating : 2.5/5


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