[time-nuts] Anyone have a comparison of the Z3805A and a Tbolt?

Rex rexa at sonic.net
Tue Sep 7 18:51:57 UTC 2010


  My Samsung 3805 says 19.5 - 30VDC. I'm running it from 24 V. I see 
from labels on the back, it has an option of 38 - 60VDC, but that's not 
the way this one was configured.

I do see, now, that the back does have a Symmetricom logo.


On 9/7/2010 9:42 AM, Bob Camp wrote:
> Hi
>
> The "China" 3805's run on 48 volts and are internally marked Symmetricom and
> marked Samsung on the outside. The cheaper "Korea" 3805's run on 24 volts
> and are marked HP internally. There is about a 5 year difference in age
> between the HP and the Symmetricom units.
>
> Bob
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Rex
> Sent: Tuesday, September 07, 2010 11:56 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Anyone have a comparison of the Z3805A and a Tbolt?
>
>    Bob,
>
> I wonder if you are really talking about Z3805A's?
>
> I know the double-oven version of 10811's were in the earlier Z3801A's;
> never heard of one in Z3805A. I have a Z3816A and a Z3805A. They both
> have MTI 260-model 5 MHz oscillators. I assume that is the "better" one
> you are referring to. My Z3805A is marked Samsung, as are all the ones I
> see coming from China.
>
> The current price seems to be more like $350 than $250 for the ones
> left. I think $350 is about what I paid for my Z3805A a bit over a year,
> or so, back.
>
> -Rex
>
> On 9/7/2010 4:34 AM, Bob Camp wrote:
>> Hi
>>
>> The "bad units" with the 10811's in them are usually marked "HP". The
>> "good units" with the true DOCXO in them are normally marked
>> "Symmetricom".
>>
>> Bob
>>
>> --------------------------------------------------
>> From: "Pete Lancashire"<xyzzypdx at gmail.com>
>> Sent: Monday, September 06, 2010 6:14 PM
>> To: "Discussion of precise time and frequency measurement"
>> <time-nuts at febo.com>
>> Subject: Re: [time-nuts] Anyone have a comparison of the Z3805A and a
>> Tbolt?
>>
>>> Is there an external way on the 3805's to id the desired 10811 ? S/N
>>> or ?
>>> Ditto on the 10811's
>>>
>>> -pete
>>>
>>> On Mon, Sep 6, 2010 at 11:31 AM, Bob Camp<lists at rtty.us>  wrote:
>>>
>>>> Hi
>>>>
>>>> I have a couple 3805's and more than a couple TBolts.
>>>>
>>>> There are two 3805's, one has the double heated 10811 the other has
>>>> a true
>>>> double oven. The true double oven / later design is the one you want.
>>>> Typically they have better TC and better ADEV at 10 seconds compared
>>>> to the
>>>> earlier part.
>>>>
>>>> The TBolt has a much better GPS receiver in it and it is far more tweak
>>>> able with the Lady Heather software. It's default settings are not
>>>> as good
>>>> as the defaults on the 3805. With some work they can be vastly
>>>> improved.
>>>>
>>>> The 3805 runs on a single 24 or 48 volt supply depending on the
>>>> model you
>>>> get. The TBolt needs +12, +5 and -12. Battery backup is easier on
>>>> the 3805.
>>>>
>>>> TBolts run $75 +/- 25. 3805's run $250 +/- $50. Shipping will be a
>>>> bit more
>>>> on the 3805.
>>>>
>>>> The TBolt wins in bang for the buck and fun to tweak categories. The
>>>> 3805
>>>> is the better plug it in and ignore it forever box.
>>>>
>>>> Both will track a cesium well at 100,000 seconds and beyond. Both
>>>> look a
>>>> lot like GPS at 100 seconds or so. Both have some significant
>>>> variation unit
>>>> to unit.
>>>>
>>>> Bob
>>>>
>>>>
>>>>
>>>> On Sep 6, 2010, at 11:13 AM, swingbyte<swingbyte at exemail.com.au>
>>>> wrote:
>>>>
>>>>> Hi All,
>>>>> Have been thinking of getting a GPSODO and I'm looking for advice
>>>> on>  what
>>>> to choose.  I haven't been able to find an ADEV comparison between
>>>> these two
>>>> units and am curious to know how their differences manifest themselves.
>>>>   Apart from the 12 satelites vs 8 what practical advantages are
>>>> there in the
>>>> 3805A over the Tbolt?  With all the extra components there has to be
>>>> something.  I notice that the ocxo is not the large Docxo of the
>>>> 3801A -
>>>> which is better?
>>>>> Thanks
>>>>>
>>>>> Tim
>>>>>
>




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