[TowerTalk] ICE 419B schematic, component values and replacement part numbers

[Dave Hachadorian]

There's a ton of history in the Towertalk Reflector Archives about these ICE 
419 units.  The David Montgomery mentioned in W5WZ's document is my neighbor 
W7WW.  He and I shared the info received from ICE with the Towertalk 
community long ago.  I think it was K1TTT who chimed in at that time, and 
recommended the CDV16 series capacitors instead of the CDV19's because the 
CDV16's are actually RF-rated.

Even after I replaced W7WW's 10 and 15 meter caps with FOUR CDV16's in 
parallel, they still ran very hot, although they never did fail, even at 100 
watts of RTTY in the NAQP contests.  The issue for the caps is RF current, 
not voltage.

The ICE 419 was a miserable little unit, plagued not only with capacitor 
failures, but dropouts on receive because the signal path goes through 10 
sets of relaxed relay contacts.  Band to band isolation is also way below 
other commercial devices.


Dave Hachadorian, K6LL
Yuma, AZ





-----Original Message----- 
From: w5wz at w5wz.com
Sent: Sunday, January 26, 2020 6:35 PM
To: towertalk at contesting.com
Subject: [TowerTalk] ICE 419B schematic, component values and replacement 
part numbers

The 15 meter section of one of my ICE 419B units failed during 2020
January NAQP SSB.  I began searching for a schematic, or a list of part
numbers, or a list of part values.  My search was mostly in vain.  I did
however find a thread here on TowerTalk from July 2011 with good
discussion about the unit and probable causes of failure. Tony N2TK
"sniff and look" troubleshooting technique quickly led to the single
burned and discolored capacitor.  Mark K5ER provided me a copy of an ICE
document listing design values.

With all that in hand, I created a reference sheet with the component
values and replacement part numbers to assist me.  Mouser did not have
correct capacitor values for the resonating section of 40 and 80 meters,
so I left that blank.

I'm sharing the reference sheet here as a resource to the group.

http://w5wz.com/files/ICE_bandpass/ICE_419_parts.pdf

I hope this can help someone else.

--Scott, W5WZ
_______________________________________________



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