The folks at Lowe UK were nice enought to steer me in the right direction
with my carrier injection problem. Any of you Lowe folks, take note!
Apparently, Q4, the carrier generator (MC14569) is being run near its design
maximum. Out of 10,000 units, I was told that 12 of them have failed because
of this chip.
I let the receiver run for about 15 minutes and the carrier injection
problem showed up in the form of the BFO frequency being drastically
shifted. I cooled the chip and normal operation of the receiver resumed.
After 2 more minutes when the chip heated up again, the problem surfaced
again. I cooled the chip once more, and once more, the receiver resumed
normal operation.
The Digi-Key part number is: MC14569BCPOS-ND They have 1743 of them in stock
at a price of $2.47 if you order less than 25 pieces.
This receiver was a stumper, but since it is only a collection of parts, it
was inevitable that would eventually get fixed. Now, if only Radio Shack has
that part in stock............................................. ..........

Pete

So I guess folks who are sufficiently handy to do repairs in their
HF-150s could do worse than sticking a heatsink onto the MC14569 while
it still works fine?

Stephan
--
Home: http://stephan.win31.de/
PC#6: i440BX, 2xP3-500E, 704 MiB, 18+80 GB, R9k AGP 64 MiB, 110W

That's what another friend suggested. It would probably be fine. I am going
to just replace the device since part of it is under the LCD. Also, since my
radio originally had a blown 1st mixer, it is quite possible that this chip
was subjected to ESD.

Pete

"Stephan Grossklass" wrote in message
...
So I guess folks who are sufficiently handy to do repairs in their
HF-150s could do worse than sticking a heatsink onto the MC14569 while
it still works fine?

Stephan
--
Home: http://stephan.win31.de/
PC#6: i440BX, 2xP3-500E, 704 MiB, 18+80 GB, R9k AGP 64 MiB, 110W

"Pete KE9OA" wrote in message
...
The folks at Lowe UK were nice enought to steer me in the right direction
with my carrier injection problem. Any of you Lowe folks, take note!
Apparently, Q4, the carrier generator (MC14569) is being run near its
design maximum. Out of 10,000 units, I was told that 12 of them have
failed because of this chip.
I let the receiver run for about 15 minutes and the carrier injection
problem showed up in the form of the BFO frequency being drastically
shifted. I cooled the chip and normal operation of the receiver resumed.
After 2 more minutes when the chip heated up again, the problem surfaced
again. I cooled the chip once more, and once more, the receiver resumed
normal operation.
The Digi-Key part number is: MC14569BCPOS-ND They have 1743 of them in
stock at a price of $2.47 if you order less than 25 pieces.
This receiver was a stumper, but since it is only a collection of parts,
it was inevitable that would eventually get fixed. Now, if only Radio
Shack has that part in
stock............................................. ..........

Pete



Can you explain this problem a little more? I did notice that sometimes
after I get a lock on a signal, and move out of range a little and you get
that howl, I have to move the dial quite a bit around to get another lock.
But, it then locks well below the frequency it locked at before.

Is this what you mean?

Lucky

No, what I mean is that the carrier insertion point, instead of being -25dB
down on the I.F. passband slope shifts to -35dB down on the slope. If you
play with a receiver that has passband tuning, the description becomes
apparent. I will describe the sound when the unit
malfunctions.....................the noise from the receiver becomes very
high pitched and voices become inaudible. The reason for this is that as the
BFO signal is moved out of the I.F. passband, the resultant audio is in the
supersonic region. Because of the low-pass filtering that is prevalent in
communications receiver designs, these high frequencies are bypassed to
ground, resulting in no apparent received audio.
Evidently, this failure mode is pretty rare, so it is pretty unlikely that
you will experience this condition with your receiver.
I hope this helps.

Pete

"Lucky" wrote in message
...

"Pete KE9OA" wrote in message
...
The folks at Lowe UK were nice enought to steer me in the right direction
with my carrier injection problem. Any of you Lowe folks, take note!
Apparently, Q4, the carrier generator (MC14569) is being run near its
design maximum. Out of 10,000 units, I was told that 12 of them have
failed because of this chip.
I let the receiver run for about 15 minutes and the carrier injection
problem showed up in the form of the BFO frequency being drastically
shifted. I cooled the chip and normal operation of the receiver resumed.
After 2 more minutes when the chip heated up again, the problem surfaced
again. I cooled the chip once more, and once more, the receiver resumed
normal operation.
The Digi-Key part number is: MC14569BCPOS-ND They have 1743 of them in
stock at a price of $2.47 if you order less than 25 pieces.
This receiver was a stumper, but since it is only a collection of parts,
it was inevitable that would eventually get fixed. Now, if only Radio
Shack has that part in
stock............................................. ..........

Pete



Can you explain this problem a little more? I did notice that sometimes
after I get a lock on a signal, and move out of range a little and you get
that howl, I have to move the dial quite a bit around to get another lock.
But, it then locks well below the frequency it locked at before.

Is this what you mean?

Lucky

"Pete KE9OA" wrote in message
...
No, what I mean is that the carrier insertion point, instead of
being -25dB down on the I.F. passband slope shifts to -35dB down on the
slope. If you play with a receiver that has passband tuning, the
description becomes apparent. I will describe the sound when the unit
malfunctions.....................the noise from the receiver becomes very
high pitched and voices become inaudible. The reason for this is that as
the BFO signal is moved out of the I.F. passband, the resultant audio is
in the supersonic region. Because of the low-pass filtering that is
prevalent in communications receiver designs, these high frequencies are
bypassed to ground, resulting in no apparent received audio.
Evidently, this failure mode is pretty rare, so it is pretty unlikely that
you will experience this condition with your receiver.
I hope this helps.

Pete

"Lucky" wrote in message
...

"Pete KE9OA" wrote in message
...
The folks at Lowe UK were nice enought to steer me in the right
direction with my carrier injection problem. Any of you Lowe folks, take
note! Apparently, Q4, the carrier generator (MC14569) is being run near
its design maximum. Out of 10,000 units, I was told that 12 of them have
failed because of this chip.
I let the receiver run for about 15 minutes and the carrier injection
problem showed up in the form of the BFO frequency being drastically
shifted. I cooled the chip and normal operation of the receiver resumed.
After 2 more minutes when the chip heated up again, the problem surfaced
again. I cooled the chip once more, and once more, the receiver resumed
normal operation.
The Digi-Key part number is: MC14569BCPOS-ND They have 1743 of them in
stock at a price of $2.47 if you order less than 25 pieces.
This receiver was a stumper, but since it is only a collection of parts,
it was inevitable that would eventually get fixed. Now, if only Radio
Shack has that part in
stock............................................. ..........

Pete



Can you explain this problem a little more? I did notice that sometimes
after I get a lock on a signal, and move out of range a little and you
get that howl, I have to move the dial quite a bit around to get another
lock. But, it then locks well below the frequency it locked at before.

Is this what you mean?

Lucky




Thanks Pete

I love the 150 and have it for like 1 month now. I'm drawn to using it. It's
extremely sensitive and holds weak signals very well. The sync actually
works.

You seem pretty knowledgable about the 150. What purpose does the double
side band serve and under what circumstances would you be applying it?

Thanks
Lucky

Thanks Pete

I love the 150 and have it for like 1 month now. I'm drawn to using it.
It's extremely sensitive and holds weak signals very well. The sync
actually works.

You seem pretty knowledgable about the 150. What purpose does the double
side band serve and under what circumstances would you be applying it?

Thanks
Lucky

I believe that this goes to a wider I.F. bandwidth, giving better fidelity.
I haven't played with that function yet, but once I get the receiver
repaired and aligned, I will give it a try.

Pete

"Pete KE9OA" wrote in message
...
Thanks Pete

I love the 150 and have it for like 1 month now. I'm drawn to using it.
It's extremely sensitive and holds weak signals very well. The sync
actually works.

You seem pretty knowledgable about the 150. What purpose does the double
side band serve and under what circumstances would you be applying it?

Thanks
Lucky

I believe that this goes to a wider I.F. bandwidth, giving better
fidelity. I haven't played with that function yet, but once I get the
receiver repaired and aligned, I will give it a try.

Pete


I think the "HiFi" mode ofers the best fidelity on the 150. I'm wondering
why Lowe implemented double side band.
You have your choice of sync in LSB, USB and AM, AM-narrow plus HiFi mode.
But also in double side band. Yes I get good results with it sometimes and
Lowe even recommends listening in double or HiFi.

Out of all my radios, this simple radio is just superb. It's quiet and has a
low noise floor. I mean I find myself using it more then my Icom R-75 and I
love that unit too.

If you've been around and used many other radios, you'll see and appreciate
the great quality in the 150. On top of all that it's a portable too. You
can take a superb rig with you anywhere you go.

I have decided not to buy the remote control for this unit as I did with my
Kenwood R-5000 and R-75. It's too much fun to use hands on. The knob and the
way it feels wins you over.

It's definitely a collectors item that's for sure.

Lucky

Pete,

What kind of equipment are you using for desoldering and soldering IC's?

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Pete KE9OA wrote:
I let the receiver run for about 15 minutes and the carrier injection
problem showed up in the form of the BFO frequency being drastically
shifted. I cooled the chip and normal operation of the receiver resumed.
After 2 more minutes when the chip heated up again, the problem surfaced
again. I cooled the chip once more, and once more, the receiver resumed
normal operation.

If you want a cheaper "freeze mist", use cans of "Dust Off" held upside
down. I believe they use the same chemical, but I get 4 12 oz. cans
of Dust Off for under $11 at Costco, while I haven't seen a 6 oz. can
of freeze mist for under $8 in 30 years.