[Icom] One big punch from W4RT

Fri, 15 Nov 2002 14:53:31 +0800

Hi Group,

IC706 (especially the very first version) is well-known for not enough mic 
gain and compression gain.  There are ways to improve the mic audio given 
in the www.icomamerica.com  trouble shooting web page.

One of the way is to modify the R236 to a higher value of 68-82k inside the 
IC706.  However, this excerise is fairly complicated for non-professional 
because it involves SMT work at the reverse side of the main unit PCB.

I ordered an One big punch from W4RT for my FT817 so that I took the chance 
to order one for my HM 103 as well.

The One big punch did give HM103 + IC706 more punch.  However, the 
compression gain of OBP itself is not that high so that I have to turn on 
the internal compressor of IC706 as well.  By setting the mic gain at 4-5 
(previously 8-10 without the OBP), I can achieve very good DX audio report 
(compressor is not supposed to be Hi-Fi for local chats).

With some experiments and audio report exchanges with DX stations in 6 
metre, the installation of OBP does give more talk power.  My current 
setting with IC706 (original version) is:  IC706 mic gain at 4 and internal 
compression gain at about 2 o'clock.

Of course, you have to bear some audio colouration in FM mode because the 
OBP inside the HM103 is always on.  Audio report for local 2 metre FM 
operation is OK and acceptable with no notable adverse effect.

As I often QRV with IC706 on 6 metre DX, I find OBP is a worthwhile 
accessory.  However, if you are only interested in local FM chats, you can 
simply forget it.

OBP is a must accessory for FT817 because the rig does not have a speech 
compressor.  If I give a 5 for FT817, I shall give a 4 for IC706.

Hope I have given you some thoughts.

73

Johnny VR2XMC

From: "Ed" <[email protected]>
Reply-To: [email protected]
To: <[email protected]>
Subject: [Icom] One big punch from W4RT
Date: Thu, 14 Nov 2002 23:52:35 -0500

Anyone have any experience with the One big punch mod for the HM 103 hand 
mic or the One big punch mic sold by W4RT? Any impressions or feedback 
would be appreciated.

ED YEARY W4TEY
325 CUMBERLAND DRIVE
HARROGATE, TN. 37752-6942

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