[ICOM] AMP INTERFACE TO 756 PRO II (CONTINUED)

[paul at w8aef.com]

Our dit element shortening observations do agree.  And I use a CMOS Super 
Keyer III, which I really like.

It will be awhile, at least after Field Day, but I will keep you posted.

de Paul, W8AEF

----- Original Message ----- 
From: "Larry Benko" <w0qe at bnk.com>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Saturday, June 18, 2005 2:02 AM
Subject: Re: [ICOM] AMP INTERFACE TO 756 PRO II (CONTINUED)


> Paul,
>
> I no longer have the 756PRO2 here since I borrowed it from a neighbor ham 
> when I made the measurements.  I do have a 756PRO, 746PRO, 765 and 
> 706mkIIG here.  The last time I measured them the first dot/dash in 
> semi-QSK and every dot/dash in full-QSK mode was shortened overall about 
> 8ms and slightly more on the 706.  The shortening was a constant time 
> amount and not dependent on CW speed and I was using an external keyer. 
> The Logikey K3 keyer I use has the option K=05 set to extend all CW 
> dots/dashes by 5ms.  This was an attempt at a compromise since I operate 
> full-QSK only some of the time.  Please let me know if you make any more 
> measurements since my measurements did not match yours.  I made the 
> original measurements as part of some other measurements and I was 
> transmitting 100w into a dummy load and sending a continuous string of dot 
> and dashes at 30wpm (dot = 40ms.).  I will try to borrow my friend's 
> 756PRO2 again and remake the measurements.
>
> 73,
> Larry, W0QE
>
> paul at w8aef.com wrote:
>
>>
>>
>> I used my Tektronix 465 dual trace oscilloscope to make my observations. 
>> If/when I put the radio back on the bench I will look again but when I 
>> made the original observation I concluded that it was in the digital 
>> portion of the radio controls, and I don't want to go there.
>>
>> And the fault was observed while operating into any one of several 
>> monoband antennas, 20 wpm cw qsk, Alpha 76 at full power out.  The 
>> trouble shooting was done into one of my several dummy loads.
>>
>> Further, my 761 and 765 did not have this characteristic.
>>
>> As an aside, how much is the first dit truncated during cw (non qsk) on 
>> your PRO2?
>>
>> de Paul, W8AEF
>>
>>
>> ----- Original Message ----- From: "Larry Benko" <w0qe at bnk.com>
>> To: "ICOM Reflector" <icom at mailman.qth.net>
>> Sent: Friday, June 17, 2005 11:58 PM
>> Subject: Re: [ICOM] AMP INTERFACE TO 756 PRO II (CONTINUED)
>>
>>
>>> Paul,
>>>
>>> I 100% disagree with you.  I have measured several Icom rigs (706mkIIG, 
>>> 746, 746PRO, 756, 756PRO, 756PRO2, 765) and on all radios both the 
>>> "SEND" line and the relay precede any RF by 9 to 11 ms. on key down and 
>>> both remain active for approximately the same time after the rf quits on 
>>> key up.  I have made some postings to this reflector with the absolute 
>>> data in the past.  Search on my call to find it.  If you have evidence 
>>> based on scope measurements (do not run scope in alt. channel trigger 
>>> mode) please post it.   My amp is keyed directly from the send line 
>>> through a transistor buffer allowing more than 1 radio to key the amp. 
>>> and have never had any problems.  If you have problems I would suggest 
>>> you try the experiment when operating into a dummy load.  If your 
>>> problems go away then the problem is RF getting into the circuit.  While 
>>> RF might get into the send line a relay is much more RF resistant.
>>>
>>> 73,
>>> Larry, W0QE
>>>
>>
>> ----
>> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
>> Icom Users Net: Sundays, 1700Z, 14.316 MHz
>> Icom FAQ: http://www.qsl.net/icom/
>>
>
> ----
> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
>
>