FRG-100/FT-840 Receive MOD
 

http://www.mods.dk/mods.php3?radio=y...ctid=2720#2720

Has anyone done the MW band receive sensitivity improvement mod on the
FRG-100? See above link. I'm presuming that the FRG-100 and FT-840 circuitry
is similar to an extent because both entered the market at the same time in
the early 1990's. I want to do a similar mod to my FT-840 for improved MW
and especially LW receive sensitivity.

73,
Thomas F. Giella, KN4LF
Plant City, FL, USA
EL87WX

Yaesu FT-840 & PSK31 Digital Mode E Group
http://groups.yahoo.com/group/yaesu_ft840
160 Meter Amateur Radio Resources & More http://www.kn4lf.com/kn4lf.htm
Daily Solar Space Weather & Geomagnetic Data Archive
http://www.kn4lf.com/kn4lf5.htm
HF/MF Radio Propagation Theory Notes http://www.kn4lf.com/kn4lf8.htm
Florida Space & Atmospheric Weather Institute http://www.kn4lf.com/fsawi.htm
Friend Website Design www.kn4lf.com

----- Original Message -----
From: "Thomas Giella KN4LF"
To: "a Longwave Radio" ; "a HCDX eGroup"
; "a Cumbre DX eGroup"
; "a ABDX eGroup" ; "a My FT-840
e-Group" ; "a Amateur Repairs eGroup"

Sent: Thursday, November 27, 2003 11:49 AM
Subject: FT-840 Receive Mod?

Happy Thanksgiving to my stateside brethren! Has anybody ever done a mod
on the fixed front end preselection circuits of the FT-840 to increase
sensitivity
on the MW and LW bands? I haven't
looked closely at the schematic yet but I would presume that it's a matter
of
defeating a resistor or two.






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I have done that FRG100 mod; it consists of removing the "T" attenuator that
is ahead of the MW bandpass filter. Since it is this type of attenuator, you
need to either place a jumper wire across the point where the two series
resistors used to be, or replace each of the series resistors with a zero
ohm resistor. Make sure that you remove that shunt resistor!
Once you do this mod, the sensitivity is comparable to the Icom R75, once
you remove its attenuator. I am not sure, though, if the same scheme is used
with the '840.

Pete

Thomas Giella KN4LF wrote in message
om...
http://www.mods.dk/mods.php3?radio=y...ctid=2720#2720

Has anyone done the MW band receive sensitivity improvement mod on the
FRG-100? See above link. I'm presuming that the FRG-100 and FT-840
circuitry
is similar to an extent because both entered the market at the same time
in
the early 1990's. I want to do a similar mod to my FT-840 for improved MW
and especially LW receive sensitivity.

73,
Thomas F. Giella, KN4LF
Plant City, FL, USA
EL87WX

Yaesu FT-840 & PSK31 Digital Mode E Group
http://groups.yahoo.com/group/yaesu_ft840
160 Meter Amateur Radio Resources & More http://www.kn4lf.com/kn4lf.htm
Daily Solar Space Weather & Geomagnetic Data Archive
http://www.kn4lf.com/kn4lf5.htm
HF/MF Radio Propagation Theory Notes http://www.kn4lf.com/kn4lf8.htm
Florida Space & Atmospheric Weather Institute
http://www.kn4lf.com/fsawi.htm
Friend Website Design www.kn4lf.com

----- Original Message -----
From: "Thomas Giella KN4LF"
To: "a Longwave Radio" ; "a HCDX
eGroup"
; "a Cumbre DX eGroup"
; "a ABDX eGroup" ; "a My FT-840
e-Group" ; "a Amateur Repairs eGroup"

Sent: Thursday, November 27, 2003 11:49 AM
Subject: FT-840 Receive Mod?

Happy Thanksgiving to my stateside brethren! Has anybody ever done a mod
on the fixed front end preselection circuits of the FT-840 to increase
sensitivity
on the MW and LW bands? I haven't
looked closely at the schematic yet but I would presume that it's a matter
of
defeating a resistor or two.






---
Outgoing mail is certified Virus Free Thanks To Grisoft AVG.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.544 / Virus Database: 338 - Release Date: 11/25/2003

Thomas, W.R.T.H.'s (one and only) 1993 Equiptment Buyers Guide states that
Yaesu's Century Frog "is based on the receiver section of the new FT-890
transceiver and should offer better dynamic range than the existing FRG-8800".
Hope this helps in your mod decision!