A little follow-up.
I looked at all four 1000B outputs with the scope; one pair is at 1.2V
rms and the second is at .7V rms. The waveform looks clean and is close
to the 1.0V and .5V described on the spec sheet so I conclude that the
oscillator is fine.
I disassembled the doubler case to check the voltage there and found
that the voltage regulator is working correctly. There are two identical
boards inside. The oscillator feeds a Mini-Circuits AK-2(+) frequency
multiplier directly and each doubled output is fed into two identical
circuits each with with 4 2n2222's, two diodes, assorted resistors and
caps thence out through a Mini-Circuits wideband transformer TMO4-6.
With the boards on the bench I jury rigged an oscillator to drive the
input and I get the same low output, albeit rather cleaner. I'm going
to order some connectors so I can be certain about the signal path and
check the doublers again.
I wonder if someone needed four low level 10MHz outputs and
ordered/modified the amplifiers to suit. I'm not sure they're working
perfectly but I suspect most of the noise I'm seeing is due to my
hook-up to the tnc connectors. I'll know more once I get some
connectors and meanwhile I'll attempt to draw a schematic of the circuit.
Thanks for everyone's comments; more later.
Bob Darby
On 4/3/2013 6:35 PM, paul swed wrote:
Bob I have no schematics but some pics might be helpful in trying to
understand why the 7818 has not incoming voltage. I speculate the unit plus
into 110 VAC?
The TNCs almost make sound like some cel tower thing.
Regards]
Paul
WB8TSL
On Wed, Apr 3, 2013 at 3:07 PM, Tom Knox<[email protected]> wrote:
Hi Bob;
I was wondering who won the unit. They are very nice oscillators. With
noise on older equipment like the 1050A I would check and/or replace caps.
I am about to do that to my own 1050A. It may not resolve the problem, but
it will eliminate that possibility. I look forward to hearing how the
problem is resolved.
Best Wishes;
Thomas Knox
Date: Wed, 3 Apr 2013 14:53:55 -0400
From:[email protected]
To:[email protected]
Subject: [time-nuts] Question about FTS 1050A
I purchased an FTS 1050 recently and after a cursory inspection of the
interior powered it up to see if it's functional.
This particular unit is a bit odd; it has the optional battery back-up,
no PPS, and instead of the usual 1Mhz, 5Mhz, 10Mhz it has four 10Mhz
outputs with tnc female connectors.
The tnc connectors are a bit of a bother but I found that the scope
probe sleeve that fits a bnc also fits into a tnc so I'm able to view
the outputs. They are not pretty, lots of hash, particularly at the
zero crossings and only about 15 to 20mV rms. That's the case for all
four.
The oscillator is an FTS 1000B-503 which is supposed to have four
buffered outputs at 5MHz; two at 1.0 V rms and two at 0.5 V rms. Two
outputs each drive a pair of frequency doublers that thus provide the
four 10Mhz outputs. I got a connector on one of the spare outputs to
see if the problem might lie in the oscillator. What I see there is a
very stable clean sine wave at 5MHz at about 660mV rms so I'm assuming
the 1000B is not my problem.
The doublers are housed in a tidy box adjacent to the oscillator with
22V and ground, two 5MHz inputs and four 10MHz outputs all in the top
cover. There is a stone cold 7818 in a TO-3 metal can mounted on one
side of the box but no external connections other than those previously
noted. It seems to me my problem must lie in this area and, since all
four circuits are similarly affected, is probably related to the power
supply housed therein.
This is probably obvious to all of you but I'm a toolmaker by trade so
this is all new to me and second opinions will not hurt my feelings.
Also does anyone have any experience inside of the doubler box or a
schematic of the standard (or any other version) doubler/divider for
these things?
Thanks for any insight anyone can offer.
Bob Darby
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