Check & exercise the RX Ant switch on the rear. Noted to cause issues.
73
Bob K4TAX
Sent from my iPhone
> On Jul 13, 2014, at 5:34 AM, "Vic Klein" <vhklein@ptd.net> wrote:
>
> Thanks for the suggestions. A few days of sleuthing and talking to Garry at
> Ten Tec led me to discover that all the input (D1-D8) switching diodes on
> the Hi-Pass filter board (81330) were "open". Garry said In4148's could be
> substituted, which I did, and now all the sections seem to test OK and
> switch appropriately...but the same symptoms remain: all functions seem
> normal, but sensitivity is off by around 4 S-units. None of the RF chokes
> seem to be open, and bypassing the Lo-pass FX board by selecting the
> external receive antenna makes no difference. I am looking at the 1st Mixer
> now, although I do get the appropriate 20dB reduction when switching in the
> attenuator, which shuts off the RF stage, so I am still befuddled.
>
> One anomally I see is the the voltages on the band switching diodes seems a
> bit low. I would have expected a lower voltage at D1 as it has more
> resistance in the path, but the reverse is true and it reads about 9.4v as
> opposed to the other 7 Hi-pass sections at about 7.25v when selected. That
> still seems plenty to bias the diodes and pull in the low-pass relays, but
> curious.
>
> =Vic=
> WA4THR
> ____________________________________________________________
> To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
> Subject: Re: [TenTec] Paragon problem
> From: Wade Staggs <tvman1954@gmail.com>
> Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
> Date: Wed, 9 Jul 2014 17:39:05 -0500
> List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
>
> *Far from being an Expert myself, The first place I would look would be the
> RX High Pass Filter Board ( 81330 ) At the Antenna Input to the High Pass
> Filter Board, there are two LC Coils and a Diode ... Any of which could be
> Shorted or open in the case of the LC Coils. You should be able to inject
> signal or an antenna input on each side of the High pass Filter Board. I
> would use a Clip Lead and touch my Antenna to the output connection from
> the board and see what happens. The High Pass Filter board uses Switching
> Diodes to select the correct Filter for each Band. I am believing that like
> Ivory Soap, 99 44/100s percent sure that the problem is somewhere on the
> High Pass Filter Board.*
> * 73 and May God Bless from Wade/KJ4WS*
>
>
>> On Wed, Jul 9, 2014 at 5:20 PM, K8JHR <jrichards@k8jhr.com> wrote:
>>
>> Hi Vic -- I am far from expert on this, but I wonder if you can locate
>> ANOTHER protective diode in the receiver circuit. I once killed my Omni
>> VII receiver by hot-switching an "active" receive only antenna - the power
>> connector arced to case ground of a bias-tee injector as I plugged it in,
>> and that fritzed the receiver. Gary at TenTec service called me to
> explain
>> it before he fixed it, and I believe he said there were multiple diodes to
>> protect the rig in such cases.
>>
>> So... perhaps you have more than one diode or fuse or other prophylactic
>> device to check?
>>
>> -----------------------------K8JHr ------------------
>
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