[Premium-Rx] WJ 8716 and WJ8718 HF

[stephous]

Geoff,

Thanks for the clarification. My preselector card is 794095-1, 20 to 30 MHz filter No. 1 (-1 penciled in). My EPROM's are all HF option. I will modify filter No.1 as soon as I find the least destructive method.

Having no preselector below 30 MHz could be an issue for AM broadcast images. Probably not a big deal. An external trap would take care of that.

One of my radios tunes from 0 to 1100 MHz. Hmmmmmmmmmm? The preselector card is also a 794095-1. It seems that cards were changed in these radios frequently. Many of them have options that were disabled. The option stickers don't always indicate what's really inside the box.

Best Regards,
Steve

PCS Associates
949 Glenneyre Street
Laguna Beach, CA. 92651-2706
Phone: (949) 376-7844
FAX: (949) 376-7866
http://www.pcsassociates.net/
  ----- Original Message ----- 
  From: Geoff Greer 
  To: stephous ; premium-rx at ml.skirrow.org 
  Sent: Sunday, August 13, 2006 5:07 AM
  Subject: Re: [Premium-Rx] WJ 8716 and WJ8718 HF 


  The card for the HFE option is a 794095-2.  They modified the filter # 1 to cover 2 - 30 MHz.  See appendix K in the option book for details. The performance your describing describes the non option card very well. WJ made a -3 version of the card that replaced filter #1 with a .1 ufd capacitor.  This one was used in the -5 version and maybe others.  Downside here is no preselector below 30 MHz.  This mod works very well.

  Geoff Greer 
  Amadeus Surplus
    ----- Original Message ----- 
    From: stephous 
    To: premium-rx at ml.skirrow.org 
    Sent: Sunday, August 13, 2006 1:20 AM
    Subject: [Premium-Rx] WJ 8716 and WJ8718 HF 


    Several of the WJ 8617/18 radios that I recently acquired are marked HFE and tune down to 2 MHz. The HF Eproms are installed in the 1st LO. The radios do not receive signals below 18MHz even though they tune down to 2 MHz. Gain drops off sharply. I'm assuming that the filters were changed at some point. I have been told that there is a filter jumpering procedure to restore HF.

    I have one of the 8618Bs on the bench. I pulled the low band filter board A3A4 and I'm trying to figure out how to jump it for HF. Do you jump L9 or the entire stage from L9 to L5? I have an 8617B-(S1) with HFE but it's bolted in the rack. It would be nice to figure this out without dismantling that radio.

    I have the manuals. How do you restore full coverage?

    Thanks,
    Steve


    PCS Associates
    949 Glenneyre Street
    Laguna Beach, CA. 92651-2706
    Phone: (949) 376-7844
    FAX: (949) 376-7866
    http://www.pcsassociates.net/


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