[TenTec] Fwd: [TentecOrionSeries] Orion II sub receiver problem

Barry Simpson vk2bj at optusnet.com.au
Thu Feb 25 05:15:42 EST 2021

Good evening all

As a final point regarding this matter, my replacement ceramic filters have
arrived from Poland. They are identified as LT 450 EW.

They are exactly the same size as the CQ 33-450 E with the same number of
pins in the same positions.

I was able to solder one into the sub receiver board where the faulty
filter had been very quickly and the sub receiver is now behaving fine.


Barry  VK2BJ

---------- Forwarded message ---------
From: Barry Simpson - VK2BJ via groups.io <vk2bj.au=gmail.com at groups.io>
Date: Thu, 18 Feb 2021 at 09:32
Subject: [TentecOrionSeries] Orion II sub receiver problem
To: Discussion of Ten-Tec Equipment <tentec at contesting.com>, <
TentecOrionSeries at groups.io>, Petr Ourednik <ok1rp at fastmail.com.au>

Good morning all

Following on from my two posts below, a few of you have asked for further
information on the fault itself and the source for replacement filters.

First of all as noted in my first posting, the symptoms of the fault are
irregular crashes and bangs from the sub receiver audio just as if there
was severe static on the band. The sub receiver S meter also registers
these crashes and bangs, even with the antenna connected to a dummy load.

The cause appears to be internal deterioration in the filters, possibly
exacerbated (made worse) by one or both sides of the filter having a DC
connection rather than being isolated through capacitors.

>From the Orion sub receiver circuit, I can see that one side of the filter
is exposed to DC but I have not done anything to change the circuitry at
this time.

The replacement filters I have bought are from PUH Hesta

They are designated LT450EW and cost US$3.28 each plus shipping.

I note that there are a couple of sources for the filters in China as well
but their websites indicated that shipping would not take place until the
end of the Chinese New Year holidays in late February so I gave those a

My filters have not yet arrived from Poland but I will make a further
posting when they do and I have fitted one into my sub receiver.

By the way, I am still looking for a replacement Orion II screen in full
working condition.


Barry  VK2BJ

---------- Forwarded message ---------
From: Barry Simpson - VK2BJ via groups.io <vk2bj.au=gmail.com at groups.io>
Date: Sat, 13 Feb 2021 at 16:55
Subject: [TentecOrionSeries] Orion II sub receiver problem
To: Discussion of Ten-Tec Equipment <tentec at contesting.com>, <
TentecOrionSeries at groups.io>

Orion II Sub-receiver problem - solved !!

I posted the message below on 18 January 2021 and as I have now solved the
problem, I thought that sharing the solution might be useful to fellow
Orion II users in the event they have similar sub receiver issues.

In summary, I spent very many hours in fruitless fault finding including
reflowing all soldered joints on the sub receiver board and changing all
the electrolytic capacitors.

Eventually, using some Freezit spray, I detected a reduction in the
crashing noise when I sprayed the ceramic IF Filter marked CQ 33-450E.

Googling that filter then brought up a host of similar problems people had
had with those types of ceramic filters in other Ten Tec models (strangely
no mention of the Orion or Orion II) and other rigs such as the Kenwood
TS2000 and some Icom rigs.

I have removed the filter and broken it open, finding some horribly
discoloured plates inside as expected from my Google searches.

Temporarily I have bridged the filter circuit with a .01 UF capacitor and
the sub receiver works like new with no crashes and bangs.

The filter is out of production but I have found an electronics dealer in
Poland who has them (or their equivalent) and I have half a dozen on the
way to me mainly as spares for any future issues.


Barry Simpson  VK2BJ

---------- Forwarded message ---------
From: Barry Simpson - VK2BJ via groups.io <vk2bj.au=gmail.com at groups.io>
Date: Mon, 18 Jan 2021 at 21:00
Subject: [TentecOrionSeries] Orion II sub receiver problem
To: <TentecOrionSeries at groups.io>, Discussion of Ten-Tec Equipment <
tentec at contesting.com>

I have a very recently acquired late serial number (black knobs) Orion II
which is in immaculate condition outside and inside.

I have not used it very much since I bought it just prior to Christmas but
yesterday I noticed that the sub receiver (standard model sub receiver) was
making intermittent loud crashing noises like receiving static and the sub
S meter was registering those crashes. The rig had been on most of the day
in a fairly warm room.

However, there were no such static crashes as the main receiver was working

Tonight, I took out the sub receiver board and cleaned all the
pins/connectors although I could not see any tarnishing anywhere.

That did nothing to cure the problem which still occurs with the antenna
connected to a dummy load.

It does not seem to occur immediately when the rig is switched on from cold
but it gradually gets worse as it warms up.

I have not identified anything specific to trigger or make the crashes
worse by tapping on components and screening boxes and wiggling capacitors
and connecting leads.

Before I start dismantling the rig and investigating further, I wonder if
anyone can identify the symptoms and suggest a possible cause.

The only thing I can think of at the moment is the power board capacitor
problem but I do not know how that would result in what I am experiencing.

All and any suggestions and pearls of wisdom would be appreciated.

Thank you in advance.

Barry Simpson  VK2BJ

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