Experiences with my Lowe HF-150
by Daniel A. Grunberg -- Kensington, Maryland U.S.A
INTRODUCTION
I own a Lowe HF-150, and I'm very satisfied with it. With a
minimum of operation, I can hear anything I want to hear. The
synchronous detector is extremely easy to use, and it works very
well. The tuning knob allows digital tuning that is so smooth,
that it has to be experienced to be believed. The HF-150 is a
wonderful radio for a MW or SW _broadcast_listener_. I've also
used my HF-150 to eavesdrop on the ham bands, on some LW beacons,
and on some utilities. While the results were good, IMHO the
HF-150 really is not meant to be a communications receiver.
ANTENNAS
I use the HF-150 and a short whip antenna, mainly for evening SW
listening (rather than DXing). I am able to carry the HF-150 with
me around my house and yard, and I much like its portability. The
SW signals are fine, with no fading even in my basement. The
synchronous detection eliminates multipath distortion (QSB), that
may be present on the signal, even if QSB is evident on other
receivers (and on the HF-150 operating in its non-synchronous
detection mode).
I have used two whip antennas with the HF-150. For several years,
I used a collapsible, non-tilting, 1 meter (approximately) whip
with a BNC connector, and I use a right-angle UHF connector (Radio
Shack 278-199) and a UHF/BNC adapter (Radio Shack 278-121) to make
everything fit together. That arrangement worked, but the right
angle adapter had to be tightened perioidically onto the HF-150's
coax connector. I've since replaced my original whip antenna with
a nice 48-inch (122-cm), stainless-steel, collapsible whip antenna
that I found at EEB (though it's not shown in their catalog.) The
whip collapses to 7 inches (18 cm). One end of the whip has a
PL-259-like connector, to mate with and screw onto the SO-239 on
the back of the HF-150. The whip antenna has an elbow joint. When
the antenna is plugged into the HF-150, the elbow joint is
1.5 inches (4 cm) away from the back of the receiver. The whip
antenna's connector allows the 1.5-inch piece to rotate 360-degrees
around the connector's center. If you rotate the plugged-in whip
so it sticks up vertically, you can tilt the whip more than 180
degrees, from a bit forward of straight up to a bit forward of
straight down.
The HF-150 and the short whip also work well for local MW stations.
They work well for MW DX stations early in the morning when power
line noise is low. However I have found that I must use the HF-150
and a 60-foot outdoor wire on MW for daytime reception of a
favorite, 50-mile-away, low-power station, because of the high
level of powerline noise at my house. The noise seems not to
bother SW reception at all.
If you live VERY NEAR a STRONG station that's within the HF-150's
tuning range, and you are determined to use an outdoor antenna, you
probably will need a notch filter, or an antenna tuner or some
other kind of preselector. If you decide to buy the HF-150, get it
with a clearly understood trial period, like I did. I'm only 0.75
miles away from a 1500 kHz AM station that gave me front-end
overload effects when I used the HF-150 with a 60 foot outdoor
antenna. (At that time I had no preselector or antenna tuner.)
Nevertheless, I decided to keep the HF-150 because it performed so
well and exhibited no overload effects, when a short whip antenna
was used. When I used the whip, I was able consistently to listen
with absolutely no interference to a 20-mile-away dawn-to-dusk
station on 1530 kHz.
DIGRESSION IN RE LOWE'S PR-150 PRESELECTOR
Because I live only 0.75 miles from a powerful, 1500 kHz station,
I must use my Lowe PR-150 Preselector to limit the bandwidth of
the signal fed to the receiver, when I use the outdoor antenna.
(I've read since that others successfully have limited the
bandwidth using antenna tuners as less expensive alternatives to
the PR-150.) Incidentally, that 1500 kHz station is so strong at
my house, that it was heard on my telephones, until the phone
company put a radio-frequency filter on my phone line. I DON'T
THINK MOST PEOPLE WILL NEED THE PRESELECTOR. I got a VERY good,
second-hand price on the PR-150 or I probably wouldn't have bought
it. IMHO, the PR-150 was produced by Lowe to take care of
situations like mine, where the HF-150's wide-open, broadband
front-end can't cope with nearby strong radio signals. The PR-150
allows me to use the outdoor antenna on MW and SW. On MW, I have
found that I can listen to a New York City station on 1560 kHz
(I live close to Washington DC) with no problem at all, even though
the station is heavily interfered with by the 0.75 mile-away,
1500 kHz station when the PR-150 is switched out of the system.
The following are three quotes are from the Lowe's PR-150 User's
Manual.
" ... the preselector's job is to pass signals in the required
frequency band and reduce the strength of signals outside the band.
To do this the PR-150 uses a continuously tunable filter ... "
" ... it will not be able to remove interference from adjacent
stations (although the PR-150 selectivity is sharp enough on medium
and long wave frequencies to have some useful effect in this area.)
What it can do however is to reduce the level of unwanted signals
that are in different frequency bands to the one being received.
This increases the readability of the wanted signal ... "
"Because it only removes signals, the preselector does NOT increase
signal strength. Indeed if you use a receiver with a signal
strength meter ... expect ... a reduction of 1 to 2 S-points ... If
a signal is very weak the pre-amplifier in the PR-150 can be
switched in to restore the original level or cause a slight
increase ... it is the signal to noise ratio that decides how
readable a signal is, not the signal strength alone."
-------------- end of DIGRESSION -------------------------
KEYPAD
The Lowe HF-150 has no keyboard. I was first attracted to the
HF-150 by its rotary tuning and digital display, which gave me the
impression of extremely smooth analog tuning. [Of course the
HF-150 is digital all-the-way, with synchronous detection, no
less.] I also was impressed with the clever way in which the
HF-150 is controlled with a minimum of knobs and switches.
Nevertheless, although the HF-150 is easily and _very_smoothly_
tuned without the keypad, eventually I found that I missed a
keypad's convenience. I bought Lowe's auxiliary keypad, and I
used Supermount (tm) strips (Radio Shack 64-2360) to attach the
keypad to the right side of the HF-150's top.
BATTERIES
The HF-150's built-in NiCad battery charger performs perfectly.
It is designed for continuous battery charging, when your not
listening to the radio. I follow Lowe's advice: I charge the
batteries continuously when I'm not listening, REGARDLESS OF
HOW MUCH CHARGE REMAINS ON THE BATTERY OR EVEN WHEN THE BATTERY IS
FULLY CHARGED. For convenience, I almost always use the battery
to power the HF-150. A fully charged set of Radio Shack's 850-maH
NiCads lets me use the synchronous detector while I listen for more
than 4 hours, before the HF-150 howls audibly. After the howling
starts, I can listen for a few more howl-free minutes if I switch
to the non-synchronous AM mode. Then the HF-150 automatically
shuts itself off to protect the batteries. The charger was
designed properly, so the fabled NiCad memory effect (it's really
an overcharging problem) never appears, even though most of the
time I don't discharge the battery fully, before recharging it.
[I have a technical article about "memory effect" which I'd be
happy to send you, if you're interested.]
Last year (2000), I e-mailed Lowe to ask what they thought about
using nickel metal hydrate (NiMH) batteries in the HF-150. Lowe
said that it would be OK to use charged NiMH batteries, but that
the batteries should not be recharged in the HF-150. This didn't
seem right to me, so I discussed the matter with the manager at
our local Batteries Plus store. The manager agreed with me. (If
you'd like my thoughts about why NiMH batteries are suitable, feel
free to e-mail me.) I've been using and charging NiMH batteries
in my HF-150 for about a year. Initially, it took about 32 hours
to fully charge the new set of NiMH batteries in the HF-150, but
the fully charged NiMHs powered the HF-150 for more than seven
hours, roughly twice as long as fully charged Radio Shack 850-maH
NiCads could. I've found that I can charge the NiMHs for as long
as I wish in the HF-150, regardless of how fully charged or
discharged the batteries are when I begin to charge them. That's
because the HF-150's NiCad charge circuit charges the NiMH
batteries at a rate that is very slow for them, and because the
NiMH batteries have no memory effect at all. Even though I don't
charge the NiMH batteries constantly, I find that not having to
worry about when to unplug the charger is very convenient.
POWER SUPPLY
I have an early HF-150 receiver. The vendor sold the HF-150 to me
without a power supply, and then he sold me a 12-volt (nominal)
wall-plug supply. When I tried everything out in the store, no hum
was apparent even in my earphones. Nevertheless, there was plenty
of hum in my earphones when I listened early in the morning, in my
quiet house. I tried using various wall-plug supplies from Radio
Shack, but could not escape the hum. Finally I found the only way
to get rid of the hum was to use an ANALOG regulated 12 Volt
power supply, and I built one. Later, I learned from Lowe that the
HF-150 requires a regulated supply, and that Lowe's external power
supply for the HF-150 is regulated. Don't settle for the hum, buy
or build an ANALOG regulated power supply.
This article was last updated on 28 February 2001.
If you have any questions, feel freeto Email me ce369@freenet.carleton.ca . I'll do my best to confuse you completely (:-). (Comments or corrections also are welcome.)
This is hit number on this document since 27 August 1997.
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