My LHS was out of Digitrax DH 123 and 163 decoder but they had a DH 121. I was told it was the same as the DH 123 but would not run on straight DC, so I bought it.
Last night I spent a hour trying to speed match it to a DH 123 and could not get close. Both engines are PK 1000 E-7's and have been speed matched before. Biggest thing is the A unit with the DH 121 starts moving at speed step 1 at around 10 Scale MPH? I have CV 2 sat at 0?
I tried to speed match the CV 5 and had to take it all the way down to 60 before they where half way close to each other? I all so sat CV 6 down to 35 so they would not interfer with each other.
Is there something I don't know about the DH 121?
Thanks for the coming answers, Ken
I hate Rust
The link below will take you to a page in the Digitrax web site that talks about the now discontinued (in 2002) DH121. If you scroll down there is info regarding Digitrax's series designations. The DH123 is a series 3 decoder while the DH121 was a series 1 decoder. Several differences are noted.
http://www.digitrax.com/products/retired/mobile-decoders/dh121/
If you paid the same amount for the DH121 as you did on the DH123 I would ask that it be replaced with a DH123. Or return the DH121 for a refund, then purchase another DH123.
They had a DH121 IN STOCK? Do they not actually sell much DCC stuff? It's been 13 years discontinued and lacks a lot of the features of the DH123.
Not sure what kind of deal you get on the DH123's, but if decoder cost is important, the NCE D13SRJ is usually cheaper and has the equivalent feature set, plus the ability to work better with LEDs. And they work fine on DCC - it's all I used until I switched to TCS to get good working BEMF. I was buying them by the 10 pack, where they came out to $11.99 a decoder.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Digitrax had a bad run of DH121s as they would lose their programming at the slightest short and would completely reset the decoder.
Digitrax did a recall of them WAY BACK when they first came out.
Obviously the one you got is really old stock!
Look for something better!
BOB H - Clarion, PA
I agree, DH126D are only $15.99 at Model Train Stuff, get your money back from the shiop you bought the DH121 from and if they seem unwilling, tell them that's fine, I'll be taking my business elsewhere!
NP 2626 "Northern Pacific, really terrific"
Northern Pacific Railway Historical Association: http://www.nprha.org/
cmrproductsDigitrax had a bad run of DH121s as they would lose their programming at the slightest short and would completely reset the decoder.
Hum, that explains the first problem I had with the DH 121. Guess I will try a complete reset and see what happens.
Far as my LHS, you folks would be tickled pink to have it 2 miles from your house like I do! Ken sells a lot of DCC iteams , but I had no idea the decoder was that old! Heck, it is made before I got into trains.
So, as far as you folks know all of the CV's are the same in the 121 as the later versions, correct?
Thank you all for your time.
Ken
Hi, Ken
When I bought my Digitrax Super Chief from a friend back in 2002 he gave me a dozen or more DH121s and I'm still using them in my "secondary" roster—engines that I don't run too often and don't need to be upgraded right away.
The 121s run just fine but they don't have the motor control and lighting functions that the more recent decoders offer. You can learn more about them here:
Good Luck, Ed
cudaken cmrproducts Digitrax had a bad run of DH121s as they would lose their programming at the slightest short and would completely reset the decoder. Hum, that explains the first problem I had with the DH 121. Guess I will try a complete reset and see what happens. Far as my LHS, you folks would be tickled pink to have it 2 miles from your house like I do! Ken sells a lot of DCC iteams , but I had no idea the decoder was that old! Heck, it is made before I got into trains. So, as far as you folks know all of the CV's are the same in the 121 as the later versions, correct? Thank you all for your time. Ken
cmrproducts Digitrax had a bad run of DH121s as they would lose their programming at the slightest short and would completely reset the decoder.
If I remember correctly - the DH121 does NOT have a reset CV
That was before they added that to the decoders - I believe the DH123s were the first of the 2 function decoders to include the Reset Option.
As for LHS - mine is just 3 miles from Home! ;-)
Randy,
It's not uncommon to find hobby shops with old stock on the shelves, not uncommon at tall. Heck, I just wandered into a shop in Chantilly Virginia which still had Atlas HO #6 switches with rivits in the point throw bar. I don't think those have been made since the 1980's, but there they were, still new in the package!
Thats a good price if you can get NCE decoders for $12 each in batches of 10! I too have switched to TCS, and have some T1's and T4's but the prices has gone up on those and I have a sizable fleet to outfit so I wouldn't mind finding "fleet" decoders for cheaper which have BEMF and decent lighting effects and plenty of the basic CV's for speed matching etc.
Rio Grande. The Action Road - Focus 1977-1983
No NCE decoder has BEMF, so the TCS is probably the best bet. That's why I switched to those.
The NCEs aren't quite as cheap as they were, but still around $13 in 10 packs, at least from Modeltrainstuff.
I've seen some old stuff hanging around my sort of LHS, they have plenty of kits with thick layers of dust on them. But kits don't get old, a 20 year old kit will still assemble the same way it did when it was new. Old locos and cars are jsut as viable, though if they are really old they might need RP25 compatible wheels installed. DC power packs have been essentially unchanged except for adding features - though old rheostat ones may not be able to control a modern lower current loco. But a decode discontinued 13 years - so it's got to be 13+ years old - to sell that as "it's pretty much the same as the one you wanted" is kind of disingenuous.
I'm not experienced enough to know if the BEMF is worth the extra cost. I've been told in MU circumstances, you have to turn it off anyway or the loco's will buck against each other so BEMF seems to be suited mainly for single unit operations? I did run some of my loco's with TCS4 decoders in MU last fall and they ran ok together however.
I was able to get some of my TCS decoders for $16 but every place I have check in the past year they seem to be over $20 now, even for the TC1 2 channel types.
Agree on the 20+ year old kits - I still get them now and then if they fit my needs/era. There are very few older loco's I would consider purchasing, certainly those with RP25 are far to ancient to be on my want list.
If anything, I have sold nearly all of my 80's/90's era diesels to upgrade better prototype matching recent loco's, such as my tunnel motors, SD45's and GP40-2's - although I wouldn't rule out a few of diesels from the 90's, such as the Proto 2000 SW1200 in the right road name, etc. I do still have quite a few 90's era loco's such as P2K GP30's, SD7's, SD9's and some KATO GP35's. Depending on ones preferences, there are many good quality loco's from the 90's but going back much further - quality is more spotty except for KATO's. I am keeping a number of my 90's era Stewart F's as they have great drives and look decent too!
As it is, was not active between the late 90's and last year and most of the decoders I had stored are now well over the 13+ category (digitrax and NCE decoders) still new in the package - but they should be usable - have light effects and basic features such as 4 digit addressing and motor speed matching etc. but certainly not up-to-date!
I run locos MUd with TCS decoders, and do not turn off the BEMF. They run fine these are usually at the club layout because until I build the layout I am designing now, I really didn;t have one big enough to justify MU locos. At shows they will run for hours at a time, and don;t overheat or fight each other or drag each otehr around. Diferent BEMF implementations might be different, but TCS's is quite good, and self adjusting, no messing with CVs. WHen I put a decoder in a new loco, for the first little while on the track it doesn;t run super smooth, than as it keeps running it gets better and next thing you know, it will creep at step one and smoothly change speeds through the whole range. The new Loksound decoders have something similar, but you need some space for the loco to run - when you enable the auto configure for BEMF, the loco takes off at full speed and then gradually slows down as the decoder calculates the optimal BEMF settings.
I've not had problems, so I generally call bunk on the idea that BEMF must be off for MUing. While the NCE decoders are very good at motor control, probably one of the best that doesn;t have BEMF, BEMF still gets you just that mch extra especially at slow speeds. Also, I'm not one of those that thinks all locos must be speed matched so they run in lockstep in order to MU them. Close is good enough - once they are pulling a train, and shuffling back and forth will even out and each will pull its share. Now, you can;t have one loco that's already moving at 20mph when the second one just starts creeping, that won;t run well at all, th faster one will be pulling the other or spinnign its wheels all the time. Just as long as they are close is plenty good enough.
Well thats been my limited experience too so I'm not sure what all the fuss regarding Mu with BEMF decoders is. FYI the loco's I ran at the show were two RTR Athearn SD40T-2's, an Athearn RTR SD45 (all the Athearns had TCS T4 decoders) and an Atlas GP40 Silver series with the factory equipped Lenz decoder.
My layout under construction is only 10x18 but I do plan on running 25 car grains and the grades are 2.9% up from staging to the yard and back down so I'll need to run at least 2, maybe 3 engines I'd guess to pull some of the trains.