[Yaesu] FL7000 (boat-anchor)

[Bob Harrison]

Hi Ross

I found this on www.mods.dk

From: Howard Ryder W4NTW at ix.netcom.com

Most Yaesu FL-7000 Solid State Linears have a hypersensitive protection 
circuit that causes the "protect" to trip when no improper conditions exist. 
This modification will desensitize the protection circuitry; but still allow 
it to function when an improper condition exists.

The modification is as follows:

PROTECTOR UNIT

  a.. Remove D7006 P/N HZ15-1L
  b.. Remove R7029 P/N J02245102
  c.. Remove R7033 P/N J02245104
  d.. Remove Q7004 P/N G3107331Q
  e.. Replace R7033 with 10K 1/4w P/N J01225103.
POWER SUPPLY UNIT

  a.. Replace C8019 P/N K13179009 WITH 1uf 50VDC P/N 59V010M5X11TR5.
This capacitor goes between the base and emitter of Q8008 P/N 2SC2229.

NOTE:
The positive lead goes to the base of the transistor.I put mine in parallel 
with th existing 0.047.

ALIGNMENT OF NEW CICUITRY

CM COUPLER

  1.. Remove the ALC cable.
  2.. Remove P06 (J04) on the Auto Tuner Relay Unit
  3.. Key the driving radio in CW (FT-757, FT-767, etc)
  4.. Adjust the power output to 400 watts
  5.. Connect the Black lead of DC Voltmeter to pin 1 and the Red lead to 
pin 3 on the Protector Unit, OR connect the Black lead to ground and the Red 
lead to TP01 on the CPU Unit (use the 0.25V range on the DC voltmeter)
  6.. Adjust TC5001 for a MINIMUM reading on the DC voltmeter
  7.. After adjustment, reconnect P06 and the ALC cable
PROTECTOR UNIT

ALC METER AND ALC PROTECTOR ADJUSTMENT

  1.. Set the ALC pot fully clockwise (CW)
  2.. Apply +9VDC to TP7001
  3.. Adjust VR7008 to the right edge of the ALC zone
  4.. Set the ALC pot fully counter clockwise (CCW)
  5.. No adjustment on the SWR Protector VR7004 is required.
IC PROTECT ADJUSTMENT

  1.. Connect the DC voltmeter to the center of VR7004
  2.. Adjust VR7004 to 3.8VDC +/-0.1V
The correct resistor and capacitor are available from Yaesu if you desire.
TB-9601- Yaesu (562)404-2700

73 de Bob G4UJS
----- Original Message ----- 
From: "Ross" <rbiggar at ihug.co.nz>
To: <yaesu at contesting.com>
Sent: Friday, January 06, 2006 5:56 PM
Subject: Re: [Yaesu] FL7000 (boat-anchor)


> Sean, and others,
> Thanks for the comments, to give you some idea of the problem, 
> transmitting into a dummy load, with the FL7000 output at only 125watts,
> it lasts 2minutes plus/minus 10secs before cutting out. I was transmitting 
> a cq in Olivia. Input to the FL7000 was 18-20watts.
> To my mind a 400 watt amplifier should take at least 200watts of digital 
> mode output without a problem.
> By the way Gary, it wouldn't be a good canoe anchor either.
> Regards to all
> Ross
>
> ----- Original Message ----- 
>  From: Sean Sharkey
>  To: Ross
>  Cc: yaesu at contesting.com
>  Sent: Friday, January 06, 2006 10:16 PM
>  Subject: Re: [Yaesu] FL7000 (boat-anchor)
>
>
>  Hi Ross,
>
>
>  Have you tried running the amp into a 50 ohm dummy load,
>  does the protection circuit still cut in?
>
>
>
>
>
>
>  Sean.
>
>
>
>
>
>
>  On 5 Jan 2006, at 21:32, Gary Smith wrote:
>
>
>
>
>
>      I need some advice on what to do with an FL7000 amplifier, (apart 
> from
>
>      using it as a boat-anchor).
>
>      It has the problem of going into protective mode at very power. I can 
> get
>
>      an output of no more than 100 watts on a digital mode
>
>      before the protective circuitry cuts in and shuts it down. Power off 
> and
>
>      on is the only way to reset it.
>
>      Theoretically the mods to eliminate this problem have been done, but 
> it is
>
>      still no better than when it was new.
>
>      On SSB the problem is similar but it cuts out at a slightly higher 
> output.
>
>      Can anyone advise me on what to do with this thing.
>
>
>
>
>
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