[Yaesu] Two Yaesu's, two TOTALLY different animals!

Mon, 25 Aug 2003 14:49:31 -0000

Hello.
Saturday evening I got my "new" Yaesu FRG-100 (Frog 100) receiver.  This
came to me with the Kiwa filter modules (3.5 & 6.0 kHz), digital keypad etc.
Last night I had a chance to do some longwave beacon chasing (NDB's) with
it.  It seems to work quite nicely for this task!

This afternoon I had a chance to make many longwave comparisons with the
Yaesu VR-5000 receiver (Wideband 100KHz to 2.6 GHz).  Except for the
nameplate there is no indication that these are even from the same company
performance wise or ergonomically!

I set it up on the switchbox so that I could change rigs and immediately
compare the two.  Selectivity/modes were similar in both rigs, AM 3.5KHz on
the Frog and AM 4 kHz on the VR-5000.  Using the sloper antenna with NO
external preamp OR Low Pass filter  the "Frog" easily picked up all the
daytime regulars at good signal strength and with NO IMD!  Ditto if I
switched in the Hustler 6BTV vertical antenna, though at slightly lower
strength.

Then I switched to the VR-5000.  First, NOTHING but IMD across the entire
longwave band until I switched in the external Low pass filter!  After
switching in the LPF it was able to hear the STRONG daytimers like FCH-344,
MO-367 etc.  NO HU-400, TCY-203 etc on the VR-5000 until I switched in the
preamp (These were all clearly and cleanly audible on the Frog).  Even with
the LPF the VR-5000 had IMD products in certain areas of the band (like 203
kHz).  Switching in the external tunable Pre-amp after the LPF and tuning it
to 203KHz eliminated the IMD on that frequency so it was DEFINITELY the
receiver front end creating it!

At first blush it looks like the FRG-100 is quite a decent little set for
beacon chasing and the best part is price wise they are a sleeper on the
used market.  I wanted to do this testing BEFORE I invested any money
obtaining narrow CW filters for it.

My intent is to install TWO CW filters, probably 125 Hz and about 400-500 Hz
on a filter switching board.  If I have a gripe about the receiver it is
that it has NO way to turn the AGC off and AGC is too slow to come back down
from a noise burst, and it has NO RF gain control.  All this will be fixed
shortly as I've found mods to reduce the AGC time constant and turn the AGC
off.  At the same point a switch for AGC off is connected can also be used
as a "Voltage control point" for RF gain control.  I intend to rewire the
"useless" squelch control to use it as an RF gain control (I've already been
studying the schematic 8^).

73 de Phil, KO6BB

DX begins at the noise floor!
[email protected]
Merced, Central California
37.18N  120.29W  CM97sh

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