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Some BB910s from China were also tested.? These were apparently manufactured on transistor equipment and required a "dummy" short middle pin. But they worked equally as well in the VXO test as those used in the Lidia RX.

**Summary document available



Chuck Carpenter, W5USJ
EM22cv, Rains Co. TX

Used one of chuck/k7qo's diode-003 charts, to compare ranges.

From 0 to 5 to 10 v the capacitance change is about:

1N4004 -- 14 7 5 pF

MV209 -- 60 23 13 pF (about the same as the small section of some
plastic variable capacitors. )

The much smaller change from 5 V to 10 V with the 1N4004 is consistent
with results I found with an SA612 VXO oscillator test fixture.

The fixture was used to measure the tuning range** with single and dual
40M crystals using various varactors and diodes used as varactors.

With the 1N4004 diodes it was quite obvious that the frequency change was
significantly more from 0 to 5 V than from 5 to 10 V.

Note that the frequency change of BB910s was much the same as the MV209s
in the VXO test.

Some BB910s from China were also tested. These were apparently
manufactured on transistor equipment and required a "dummy" short middle
pin. But they worked equally as well in the VXO test as those used in the
Lidia RX.

**Summary document available



Chuck Carpenter, W5USJ
EM22cv, Rains Co. TX

Lee,

My interest was mostly the VXO tuning ranges.? But I did measure some.

For the same voltage range of 0? 5 and 10 the
BB910 measured, 52? 22? 8 pF comparable to the data sheet curve.

This is the link from last March, but it's no longer active.

?<

At 04:06 PM 11/24/2017, Leland L. Bahr wrote:

So what were your reading for the BB910 ???

Lee, w0vt

Some BB910s from China were also
tested.?? These were apparently manufactured on
transistor equipment and required a "dummy"
short middle pin. But they worked equally as
well in the VXO test as those used in the Lidia RX.

Chuck Carpenter, W5USJ
EM22cv, Rains Co. TX