On Fri, 15 Apr 2016, sctvguy1 wrote:

On Fri, 15 Apr 2016 07:47:44 -0700, karabas2001 wrote:

On Friday, April 15, 2016 at 3:06:45 AM UTC-4, wrote:
Hi I have a Kenwood R 1000 , love it . . it developed power problems .
i have since stripped the power board . .unfortunately I cant get most
of the important parts . do you know of any second hand or new boards
available I really want this radio to work again. Regards Peter ZS5
PX

What parts do you need ? Nearly anything inside a radio of this vintage
should not be a problem .

Too bad it does not have tubes that can just be replaced.

But then you'd have all those paper capacitors that need replacing, and
maybe it's old enough that the resistors have changed value and may need
replacing too.

Like he said, there's a period when most parts in solid state radios are
still readily available. Maybe that's after silicon transistors took over,
I gather those with HRO-500s have had some problem replacing germanium
transistors (and probably the germanium transistors need replacing because
they've gone bad over time). But it's also a period before large scale
integration came along, so the ICs are plentiful but common analog or TTL.

I can't imagine anything from that vintage in the power supply being
really hard to get, a regulator IC might be hardest, but I suspect it
wouldn't be something hard to get now. The rest would be common
electrolytics, power diodes, maybe some transistors. They can be found,
and if not, suitable substitutes can be found.

It's later that seems to be a problem.

Michael

On Friday, April 15, 2016 at 9:38:06 PM UTC-5, Michael Black wrote:
On Fri, 15 Apr 2016, sctvguy1 wrote:

On Fri, 15 Apr 2016 07:47:44 -0700, karabas2001 wrote:

On Friday, April 15, 2016 at 3:06:45 AM UTC-4, wrote:
Hi I have a Kenwood R 1000 , love it . . it developed power problems .
i have since stripped the power board . .unfortunately I cant get most
of the important parts . do you know of any second hand or new boards
available I really want this radio to work again. Regards Peter ZS5
PX

What parts do you need ? Nearly anything inside a radio of this vintage
should not be a problem .

Too bad it does not have tubes that can just be replaced.

But then you'd have all those paper capacitors that need replacing, and
maybe it's old enough that the resistors have changed value and may need
replacing too.

Like he said, there's a period when most parts in solid state radios are
still readily available. Maybe that's after silicon transistors took over,
I gather those with HRO-500s have had some problem replacing germanium
transistors (and probably the germanium transistors need replacing because
they've gone bad over time). But it's also a period before large scale
integration came along, so the ICs are plentiful but common analog or TTL.

I can't imagine anything from that vintage in the power supply being
really hard to get, a regulator IC might be hardest, but I suspect it
wouldn't be something hard to get now. The rest would be common
electrolytics, power diodes, maybe some transistors. They can be found,
and if not, suitable substitutes can be found.

It's later that seems to be a problem.

Michael

Ask bigclivedotcom ...at Youtube. Looka here, do you use a Mac computery? Don't plug in one of those hub thangys, just ask bigclivedotcom

Michael Black wrote:
I gather those with HRO-500s have had some problem replacing germanium
transistors (and probably the germanium transistors need replacing because
they've gone bad over time).


Germanium transistors are cheap and plentiful on eBay. You need to figure
out which ones made in the Soviet Union replace the ones made in the west.

Germanium transistors were mostly PNP, so NPN ones are harder to find.

Replacements for CK722, 2n404, 2n107 and 2n109 are less than a $.25 each
including postage. I am sure there are others, but those were the ones
I needed.


I found 100 assorted Tesla (eastern Europe, not actually Soviet) ones
for less than $.50 each including postage.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

On Wed, 20 Apr 2016, Geoffrey S. Mendelson wrote:

Michael Black wrote:
I gather those with HRO-500s have had some problem replacing germanium
transistors (and probably the germanium transistors need replacing because
they've gone bad over time).


Germanium transistors are cheap and plentiful on eBay. You need to figure
out which ones made in the Soviet Union replace the ones made in the west.

Germanium transistors were mostly PNP, so NPN ones are harder to find.

Replacements for CK722, 2n404, 2n107 and 2n109 are less than a $.25 each
including postage. I am sure there are others, but those were the ones
I needed.

At least some of those are audio bandwidth transistors, the HRO-500 of
course needs transistors good in the shortwave and low VHF segment.

I just know I've seen people writing about restoring their HRO-500s and
other things with germanium diodes, and getting replacements has been some
sort of an issue.

I probably have some germanium transistors around, unless I tossed them.
There was a period in the seventies when the local electronic store, which
also sold surplus (Etco Electronics, they later moved their base to the US
to do mailorder) was offering great deals on germanium transistors, but
their selling point wasn't that they were germanium. It was that they had
good frequency response. I did buy a lot of those back then.

In some ways it is a surprise the HRO-500 could come out in 1964. It's
not that long before that transistors were for audio and at best the AM
broadcast band, yet here is a receiver that from reports is fairly good,
it wasn't a consumer radio, but which could be transistorized. The big
wave of transistor shortwave receivers came towards the end of the
sixties, and some, like my Hallicrafters S-120A, were awful, in part
because they were transistorized. Lots of overload, on top of the usual
issues related to low end receivers.

Michael

Michael Black wrote:
At least some of those are audio bandwidth transistors, the HRO-500 of
course needs transistors good in the shortwave and low VHF segment.

I expect they are there too. The ones I am interested are for yellow
boxes made around 1963 which use audio transistors. Most of them are
either oscillators to boost DC voltage, some are dc amplifiers.


I just know I've seen people writing about restoring their HRO-500s and
other things with germanium diodes, and getting replacements has been some
sort of an issue.


The Soviet D9b diodes make great detectors and are about a penny each,
including postage. They were half that because the lower case b in the
Cyrilic (Russian) alphabet looks like a number 5, and they were listed
as D95 diodes, which no one could find any specs on.

I think I had something to do with the price rise, when I commented on
the price on several groups, the listings were fixed and the price went up.

There even are 1n34a diodes still made with germanium in them. Most of the
so called germanium diodes are actualy silicon. They make finding the
real ones difficult as eBay vendors don't differentiate.

I have a few UK germanium diodes, that have real gold in them, and are
much better detectors. I found them on eBay for 1 UKP each. I am saving
them for a special project, when I think of it.


I probably have some germanium transistors around, unless I tossed them.
There was a period in the seventies when the local electronic store, which
also sold surplus (Etco Electronics, they later moved their base to the US
to do mailorder) was offering great deals on germanium transistors, but
their selling point wasn't that they were germanium. It was that they had
good frequency response. I did buy a lot of those back then.


If you can look up what they were, I would be interested in finding out.

Geoff.


--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379