[Milsurplus] RBZ vs RBZ Special?

[WA5CAB at cs.com]

Ian and Mike,

I don't know how the change was effected. Doubling in the oscillator is I 
guess a possibility. But I just had a look at the schematic again and don't 
see how the antenna and RF tuning could have been doubled without changing 
something. The oscillator has C3 that could have been changed maybe. But the 
RF and Antenna tuned circuits consist of only the tunable coil and a trimmer 
capacitor (and the antenna). The only thing I can think of that would work 
would be adding a fixed capacitor in series with the trimmers. From the 
message traffic, there appear to be at least two modified receivers in list 
member's hands. We can speculate as to how it was done but the only way to know 
for certain absent changes in the manual (which several people have said did 
not happen) is to open up a modified receiver and find out. And I only have 
an unmodified one so I can't do it.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480 

In a message dated 09/17/2013 11:03:12 AM Central Daylight Time, 
ianmwilson73 at gmail.com writes: 
> If the frequency coverage has doubled, does this suggest that
> 
> a harmonic of the original LO is being used?
> 
> 
> 73, ian K3IMW
> 
> 
> 
> 
> On Tue, Sep 17, 2013 at 8:58 AM, Mike Feher <n4fs at eozinc.com> wrote:
> >> Bob -
>> 
>> Not a matter of right or wrong, I am just curious as to how this 
>> frequency
>> change may have been performed in the field as claimed on here. - Mike
>> 
>> Mike B. Feher, N4FS
>> 89 Arnold Blvd.
>> Howell, NJ, 07731
>> 732-886-5960
>> 
>> 
>> -----Original Message-----
>> From: milsurplus-bounces at mailman.qth.net
>> [mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of WA5CAB at cs.com
>> 
>> Sent: Tuesday, September 17, 2013 11:46 AM
>> To: milsurplus at mailman.qth.net
>> Subject: Re: [Milsurplus] RBZ vs RBZ Special?
>> 
>> Oops, you're right.  Then the coils were not changed.
>> 
>> In a message dated 09/17/2013 10:31:26 AM Central Daylight Time,
>> n4fs at eozinc.com writes:
>> >This receiver tunes with slug tuned coils as I recall, and not a
>> >variable condenser. 73 - Mike
>> >
>> >Mike B. Feher, N4FS
>> >89 Arnold Blvd.
>> >Howell, NJ, 07731
>> >732-886-5960
>> >
>> >
>> >-----Original Message-----
>> >From: milsurplus-bounces at mailman.qth.net
>> >[mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of WA5CAB at cs.com
>> >Sent: Tuesday, September 17, 2013 11:28 AM
>> >To: milsurplus at mailman.qth.net
>> >Subject: Re: [Milsurplus] RBZ vs RBZ Special?
>> >
>> >Double the coverage would be expected if the same tuning capacitor is
>> >used (for examples, consider the TCS and the SP-200 Super Pro family).
>> >
>> >Robert Downs - Houston
>> >wa5cab dot com (Web Store)
>> >MVPA 9480
>> >
>> >In a message dated 09/17/2013 10:11:58 AM Central Daylight Time,
>> >n4fs at eozinc.com writes:
>> >>Joe -
>> >>
>> >>Does the frequency scale in the Special still increase in frequency
>> >>when the dial is turned clockwise, or, does it decrease. It is also
>> >>interesting to note that the frequency range covered in the Special
>> >>is twice as wide. 73
>> >>-
>> >>Mike
>> >>
>> >>Mike B. Feher, N4FS
>> >>89 Arnold Blvd.
>> >>Howell, NJ, 07731
>> >>732-886-5960
>> 
>> Robert &Susan Downs - Houston
>> 
>> 
> 
> 
>