[UK-CONTEST] Fw: Key Click Comparisons

[Bob Henderson]

----- Original Message -----
From: "Bob Henderson" <bob at cytanet.com.cy>
To: "FOCmembers" <foc_members at yahoogroups.com>
Sent: Thursday, March 27, 2003 3:25 PM
Subject: Key Click Comparisons


> Despite my protestations that my signals are clean I have succumbed to
> suggestions made by Jens DL7AKC and Ken DL8LBK that I do some bench checks
> on my FT1000MP and MkV Field.
>
> As I don't have the necessary equipment to make stand alone measurements
> with objective integrity, I have made some comparative tests on various of
> the radios I have kicking (or clicking) around in the shack here.  I found
> the results interesting.  So much so that I have now modified my early
> FT1kMP using the W8JI recommendations.
>
> To carry out the comparative tests I sent a series of dots at around 30
wpm
> from each rig in turn at 50W output into a 50 ohm dummy load.  I used an
> Omni VI+ with I/F b/w at 250 Hz as the receiver, connected to my 4 ele 15m
> yagi which was pointed towards the shack.  This setup gave me a received
> signal of exactly S9 on the Omni VI s-meter from each rig.  I tuned to
> either side of the received signal until the s-meter indication dropped to
> S1 and tabulated the bandwidths so determined for each rig below.  You
will
> notice that my early MP was easily the worst click producer but after
> fitting the W8JI mod is significantly improved.  The Inrad mod is
> essentially the W8JI mod but without the critical components selected on
> test.  As expected, the Inrad mod also made a significant improvement but
> better was achieved with the SOT components.
>
> The TS870 has adjustable rise time so I checked it at 2 mS, 4 mS and 8 mS.
> It was the cleanest of the bunch at 8 mS but a little too soft for QRQ.
>
> TS930                          1.6 kHz
> TS870 (2mS)               2.0 kHz
> TS870 (4mS)               1.5 kHz
> TS870 (8mS)               1.0 kHz
> K2                               1.5 kHz
> MP MkV Field             2.0 kHz
> MP                               3.4 kHz
> MP (Inrad mod)           1.7 kHz
> MP (W8JI mod)           1.3 kHz
>
> FWIW
>
> 73
>
> Bob 5B4AGN, P3F
>
>
>