kkim@uiucdcsb.UUCP (02/09/87)
/* Written 1:23 pm Feb 5, 1987 by kkim@uiucdcsb.cs.uiuc.edu in uiucdcsb:misc.consumers */
/* ---------- "2400 bps modems?" ---------- */
I am considering buying a 2400 bps modem. I looked up Byte magazine and
I found following ones which seem relatively cheap:
1. Eclipse 2400 External EDP-2400 $299
2. Anchor Lightning $299
3. THE 2400 $259
(Thompson, Hariman, and Edwards)
4. CTS 2424 ADH async/sync $269
(CTS Fabri-Tek Inc., Datacomm Produce Division)
5. Incomm (upgradeable to 4800) $295
Do you have any good or bad experience with them?
By the way, what kind of modulation is adopted in 2400 modems? An article in
Byte said 600 baud * 4 (QAM) = 2400 bps based on the CCITT V.22bis method.
Is it the method almost all of 2400 bps modems adopt?
How about 1200 baud modems using Bell 212 (or 212A) method?
In some book, I saw that it uses FSK(Frequency Shift Keying); the manual
of my 1200 bps Anchor Volksmodem 12 says that it uses PSK (Phase Shift
Keying) without saying how-many phase(2-phase or 4-phase).
The same article in BYTE says that 600 baud * 2 (4-phase PSK) = 1200 bps.
Which one is correct?
Do you have any correct information? Or did it change as time goes on?
Kyongsok KIM
Department of Computer Science
University of Illinois at Urbana-Champaign
my addresses are as follows:
network address
------- -------
arpanet kkim@b.cs.uiuc.edu (domain format) OR
kkim@uiuc.arpa (alias)
csnet kkim@uiuc.csnet,
kkim%uiuc@csnet-relay.arpa (obsolete), OR
kkim%uiuc.csnet@csnet-relay.arpa (obsolete)
usenet/uucp {seismo, pur-ee, ihnp4, convex}!uiucdcs!kkim
/* End of text from uiucdcsb:misc.consumers */chow@batcomputer.tn.cornell.edu (Christopher Chow) (04/09/87)
I'm thinking about getting a 2400 bps modem in the near future, and I'd like
to solicit some comments. Looking through _Byte_ and _Infoworld_ and a few
other sources I came across a few models and prices:
Model Approx. Price
--------------------------------------------------
(1) US Robotics Courier 2400 $350
(2) Microlink 2400 350
(3) Qubie 2400 230
(4) 'private label version' of Micom M3124H 300
(5) Racal-Vadic Maxwell 2400VP 435
My main problem is that I'm pretty unfamiliar with these models (except for
the R-V, which we have at work) so making an intellegent choice between them
is difficult.
I guess I should list my requirements: Aside from the ability to maintain a
2400 bps connection through not-the-world's-greatest-lines, the modem must
be external and Hayes compatible. This dosen't narrow it down very much, so
there are other features which would be nice to have around:
a. MNP error correction
b. speed conversion (i.e, computer sees same baud rate regardless
of actual connect speed)
c. call monitering (i.e, busy signal detect)
With respect to (a), I know that (5), and (4) have it. Do any of the others
have MNP? If so, up to what level of implentation? BTW in case you're
wondering (4) is from an Shamrock ad on p.24 of the March 30 _Infoworld_. [
Does anyone know anything about this modem? It looks reasonably good in the
ad.] I also know that (b) & (c) are avaiable in (5), but I'm totally
clueless if any of the others have them.
Is there anything else I should be considering? Can someone comment of
quality and support? What about bugs? I seem to recall that there were
some heat related problems with the USR Courier 2400 and it had problems
talking to other 2400bps modems when it was first released. Were these
problems fixed? What should I buy? Are the prices I found reasonable, or
can the modems be had for less? What are your experiences with 2400 bps
modems?
thanks in advance,
Christopher Chow
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\---------------------------------------------------------------------------/berger@datacube.UUCP (04/15/87)
I strongly recommend the Multitech Multimodem 224E. We get them for under
$500 with MNP support. It supports 300 1200 and 2400 baud. Its hayes
compatable and is generally nice to use. We've been using them for
years now and have had very little problems.
Our source is:
Direct of New England
One Mountain Rd
Burlington, Ma 01803
617-272-6565
Don Cadieux
Bob Berger
Datacube Inc. Systems / Software Group 4 Dearborn Rd. Peabody, Ma 01960
VOICE: 617-535-6644; FAX: (617) 535-5643; TWX: (710) 347-0125
UUCP: ihnp4!datacube!berger
{seismo,cbosgd,cuae2,mit-eddie}!mirror!datacube!bergerroy@phri.UUCP (Roy Smith) (04/24/87)
In article <102000003@datacube> berger@datacube.UUCP writes: > I strongly recommend the Multitech Multimodem 224E. We get them for under > $500 with MNP support. While I'm not sure I would rave about the MT224E, I guess it's about as good as any modem we've had and better than many. The best price I've seen is from Advanced Data Products in Gaithersburg, MD 800-732-7654. The price sheet I have on my desk is 6 months old and says the MT-224EH (desk-top) is $409 but I remember seeing a more recent flyer from them saying it's about $350. Call them and ask for their dealer price list; they seem to be willing to give dealer prices to anybody who buys more than one of an item. The 224ER (rack mount) is the same price, which is annoying because it's just the card from the EH without the plastic case and power supply. I suggest getting the EH and saving the case and supply in case you want them later. Note: I'm not 100% sure the EH and ER use the same phone connection; better check first. The ER uses a DB-9 to RJ-11 cord, the EH may use an regular RJ-11 to RJ-11. -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016 "you can't spell deoxyribonucleic without unix!"