Can anyone tell me what the alphabetic letters at the end of the Motorola DCT model number mean? For example, what is the difference between DCT2244/1661/ABCDEFG and DCT2244/1661/ACDEG

Thank you!

They designate which features are included on the base model. I can't remember most of them, but I think "F" is for the built-in telco modem for cable systems without an RF return (rare these days). Other letters are for IR port, SPDIF, etc.

Here's a comprehensive list of what all those numbers & letters after 'DCT' mean. This is only for the DCT1000/1200/2000 series, I don't know if any of this applies to the 2500.

Options Feature
A 8 MBits DRAM for MPEG-2 with full resolution B frames
B Analog Descrambling (GI only)
C Bit Mapped Graphics
D BTSC Stereo Decoder
E Audio Loop Through Connector
F RF Bypass
G RS232 Connector
H High Power IR Blaster Connector
I Stereo Privacy on Analog Channels
J S-Video (Future)
K Home Theater Package S-Video and SPDIF (AC-3)
L Enhanced Home Theater. All Audio outputs active regardless of content
M Analog Descrambling Zenith Only
N Analog Descrambling GI/Zenith/Tocom (Future)

The DCT1000/1200 also has a R option which is the definition of the
platform:

R1 QUOD
R2 AVI

As for the numbers, DCT1abc would mean DCT1000, DWT1abc would mean DCT1200,
and DCT2abc would mean DCT2000 series.

a=Modulation Technology (1=64 QAM, 2=64/256 QAM)
b=Return Path (1=One Way, 2=StarVueII RF (DCT2000 Integrated)
3=StarFone(300baud) (DCT/DWT: Not a option),
4=StarFone II (14.4kbps) (DCT 2000:SVT-II Integrated),
6=StarFone II (14.4kbps) (DCT 2000:No Diplexer)
Return Path notes: RF Return is standard on the DCT 2000. Telco
Return SFT-II(Option 4) is optional. Option 4 indicates
both RF and Telco return. Option 3 is for DCT 1000/1200 only.
Option 6 is for DCT 2000 only (RF Return diplexer removed.)
c=Output Channel (4=VHF(3/4), 6=UHF(46-60)

The boxes has three sets of numbers so as a example, DCT2abc/defg/options.

d=Signal Format (1=NTSC, 2=PAL-P (Future), 3=PAL-B/G, 4=PAL-N (Future),
5=PAL-M (Future), 6=PAL-D/K (Future))
e=Out of Band Frq (MHz) (1=75.25, 2=72.75, 3=104.2, 4=125.0, 5=In-Band,
6=Agile OOB) - no idea what 5 and 6 is.
f=App Memory - This one is still blank so no one knows what each number is.
g= Brand Label (1=None, 2=Comcast Logo)

Example 1:

DCT2224/1261/ would be:

DCT 2000 series, 64/256 QAM Modulation Technology, StarVue II RF Return
Path, VHF (3/4) Output Channel/NTSC Signal Format, 72.75Mhz Out of Band
Frequency,App Memory option 6, No Brand Label

Example 2:

DCT2224/1161/ would be:

DCT 2000 series, 64/256 QAM Modulation Technology, StarVue II RF Return
Path, VHF (3/4) Output Channel/NTSC Signal Format, 75.25Mhz Out of Band
Frequency,App Memory option 6, No Brand Label

Example 3:

DCT2244/1161/ABCDEF:

DCT 2000 series, 64/256 QAM Modulation Technology, StarVue II RF+StarFone
II Return Path, VHF (3/4) Output Channel/NTSC Signal Format, 75.25Mhz Out
of Band Frequency,App Memory option 6, No Brand Label/8 MBits DRAM for
MPEG-2 with full resolution B frames,Analog Descrambling (GI only),
Bit Mapped Graphics,BTSC Stereo Decoder,Audio Loop Through Connector,
RF Bypass

Example 4:

DCT2244/1661/ABCDEF:

DCT 2000 series, 64/256 QAM Modulation Technology, StarVue II RF+StarFone
II Return Path, VHF (3/4) Output Channel/NTSC Signal Format, Agile OOB Out
of Band Frequency,App Memory option 6, No Brand Label/8 MBits DRAM for
MPEG-2 with full resolution B frames,Analog Descrambling (GI only),
Bit Mapped Graphics,BTSC Stereo Decoder,Audio Loop Through Connector,
RF Bypass

Enjoy!

Oh perfect!!! Great information! Thank you very much. Thats exactly what I needed!