- A single mixer board is completed. I am not sure of a good way to
test this one yet though as am afraid to couple my signal generator
directly to the board. (Even with it selected for lowest output, I have
gotten shocked from my sig gen many times.)
- VFO board completed. Output is good on a freq counter. This was a fun
board. I like building LC oscillators as they always seem to need a bit
of tweaking to get them where you want. This one was no exception, but
only required minor experimenting by compressing the L6 coil windings
and adjusting the capacitance value at C3. I would think this is normal
due to construction differences.
When I first checked the VFO, it was running
4.57-4.96 Mhz with 1/2 CT trimmer, so I was low and needed to expand
the tuning range as well for the target 5.0-5.5 Mhz. I studied the
component table in the article for different freq's and I think was
successful by changing C3 from the 120pF to a 62pF with a 15pF in
parallel with it. I am lucky I had these values (And they were NPO's!)
in my junk box.
The final tuning range with CT trimmer at midrange
is 4.97-5.52 Mhz for 550 Khz range. Of course this leaves me with a bit
more tuning cushion than is ideal, but I think its better to have some
tuning cushion at both ends. Too much tuning cushion though would just
eat up band spread and probably make any tuning adjustment that much
coarser, so I wanted some cushion over the 500 Khz, but not alot.
I was also pleased this board worked because this
was the first circuit board requiring the dreaded "Dual Gate MOSFET". I
knew these pricey little transistors were very susceptable to static
damage and so I was little nervous about that too. There were not one,
but TWO typos on the circuit board component
placement diagragm for the VFO. Q6 and Q7 were swapped, and the center
tap and ground connections of L6 were labeled as going into the wrong
holes as well. These kinds of things are probably among the culprits
that got me 17 years ago.
It looks like just one more board left for the basic 80M receiver - and
that would be the the very 'busy' IF AMP board. It is no accident I am
saving this board for last. I think everything is working so far, I'm
in practice now, have a little bit of confidence, and 1/4 lb. of solder
-IF board completed, less any crystal filter or the filter matching
networks. I tried to be very careful around Q9 and Q10. I grounded the
circuit board holding fixture, then touched the solder iron to the
fixture just before soldering up the Dual Gate MOSFETS.
I almost made a mistake and soldered one secondary
lead of T4 into wrong hole but caught my error later during the work. I
am all for ground plane construction, but I think stuffing a board with
many components close together such as this, it was actually a good
thing that I chose single sided board as I could actually see the
traces through the material aiding proper installation.
Although on this board component overlay drawing I
noticed that the 100 and 560 ohm resistors above Q9 are swapped in the
wrong holes, so I installed them in eachothers' positions so they agree
with the schematic. My board artwork is as supplied from the ARRL in
1992 - so hopefully this is corrected on current copies.
There is also a pair of hand written corrections
from the ARRL on the supplied drawing about adding a 2.2k resistor
across the primary of T4 and a typo correction where one of the
two 1M AGC resistors is mistakenly indicated as a 1K on the component
I mounted the C16 trimmer manhattan style again and
applied power to the board for a smoke check. Checked OK, so then
proceeded to adjust the R10, AGC SET trimmer - but was getting some
weird readings. When I was still getting voltage readings with the DMM
no longer connected to the IF board I decided to try another meter. Yep
it was the batteries in the first meter! What is my luck of checking
out somthing with another thing that itself does not work! Anyways AGC
no signal voltages were easily adjusted per the article with the second
- Spent some time temporarily hooking up all six boards to power and
eachother per the flow diagram, powered them up, hooked up my loaded
80m inverted vee antenna and was rewarded with first signals on 80m!!!
There is no filter installed as was my intent to try testing without
one installed, but there aren't that many signals on 80m in August
The action of the preselector on this receiver is
really incredible and I can tell right now it is going to take 2 hands
to tune it :) It was even driving a small 4" speaker so that I could
hear the stronger signals without headphones on, but the AF board is
not designed for speaker operation. I will try to get a testing picture
here very soon, but is so good to know that my second time around with
"The Progressive Receiver" I am coming out OK.
I need to get some advice on my BFO frequency and
possibly change to a larger, more 'rubbery' crystal for my panel
mounted BFO, or may end up obtaining the INRAD 9.0 Mhz LSB & USB
crystals then make another BFO to cover both sidebands with a switch. I
will get this issue ironed out and then begin work on the other mixer,
40m oscillator, and 40m filter boards.
- More helpful emails from K5IRK and W7ZOI suggest that I need to get a
full size 9.000 Mhz crystal in the BFO board for better VXO range as is
required using a single BFO for USB and LSB.
- Uploaded a YouTube video of this board work so far spread out on the workbench and listening on 80m.
"A Progressive Receiver First Signals"
- I read at one of the online references for laser toner circuit board
etching (Bottom of page) that coating the board with a clear spray will
preserve the copper while still allowing decent solderability. I did
not believe this - but thought I should try it.
So I performed an experiment on scrap circuit board. Sprayed the copper side with
clear enamel, let dry one hour, then tryed soldering through the enamel.
It just took a extra couple of seconds for the iron to do its work, but
the solder job turned out great! It is my plan then on future boards
after soldering all components in to coat the copper with clear enamel
to preserve the state of the copper. I should only have to solder a few
inter-connections on any board afterwards anyway.
- INRAD Experimenter's Filter Kit and larger replacement 9.000.0 Mhz
BFO crystal ordered for better VXO range. I elected to start with
the 2400Hz filter model as I like using the wide bandwidth to search
the band first.
I plan on adding at least one active audio filter,
so the idea at this point is 2400 Hz IF filter with active AF filter
for CW unitl I get around to adding another CW bandwidth IF filter.
However I will install IF filter switching circuitry with this first
2400 Hz IF filter.
- INRAD parts arrived ....2 days to IL from CA via cheap method is
FAST. I am impressed that they included regular leaded caps in addition
to the SMD caps in the crystal filter kit (Your choice). This eased my
mind as I really did not want to get into SMD anyway.
INRAD 9.000.0 BFO crystal installed and definately
'rubbers' much better than the smaller one from Mouser. I measured a
4.5 Khz swing now with my 45pF air variable.
- First mixer, 40m oscillator, and 40m filter boards etched. First mixer board assembled.
- Completed the 40m converter oscillator using a 3.300.0 Mhz crystal
from Surplus Sales of Nebraska. However during testing I got my first
'wiff' of smoke that I believe came from the 39 ohm resistor of the DC
power input network. I had this network mounted on the 1st mixer board
so that I only had to build one of these networks for the
converters oscillators, and the DC would be switched with the
oscillator inputs. I substituted the DC input network from the BFO into
the 40m converter oscillator for troubleshooting, but then got a wiff
of smoke from that network too, so I knew the problem was in the 40m
converter oscillator board.
Really there was not that much going on with the
converter parts - but after double checking everything I decided to
As it turns out that was the problem as it then fired right up, tweaked
it for max output and reliable starting, and was right on freq.
I am fairly certain that I did not have primary and secondarys crossed
up. What I think it was is the CT relationship to the primary leads as
its not really a CT but rather a tap at 13 of the 65 turn primary. I
had to lay this crystal down as the leads could not be bent. Glad
everything worked out.
On with the 40m input filter next.
- The 40m input filter has been completed a couple of days now. I have
coarsely aligned it using the old Heathkit signal generator. There is
no RF amplifier called out for 40m - hence the jumper wire between
points X and Y on the board. I am been working through some issue(s) on
40m though. There is no band noise at all. I have only been able to
hear a couple of 40m signals very, very faint one time when connected
to my 40m vertical antenna. I have done alot of board swapping,
component swapping, re-winding, measuring, etc., but am still stumped
on why 40m is 'dead' with or without the 40m input filter inline with a
sig gen or on the air to antenna.
John Lawson, K5IRK, has been working with me
via several emails on this problem and seems as determined as me to get
to the bottom of it.
- After a few days of troubleshooting
the problem on 40m, I decided to take a break from that issue and
construct the INRAD #351, 2400Hz, 4 pole crystal filter. It does not
come with a board, so the board pattern is my own - allowing for the
pair of 200 to 50 ohm bifiliar matching transformers.
A design that
W7ZOI had suggested and sent me.
- Well after several more helpful emails from John Lawson, finally
stumbled in to my problem on 40m. I had installed the windings for the
T5 bifiliar matching transformer in the wrong transformer holes on the
mixer boards. This was also the case on the second mixer. These
transformers are still not intuitive to me as they are drawn
schematically, but hey I still don't get Roman numerals either :)
With these two circuit corrections, the PR RX came to life on 40m, and is even better now on 80m.
I have some tidying up to do on the boards after
double checking the AGC control circuit. Then will be time to order
some parts for the other bands, and enclosure, accessory circuits, etc.
Plenty to do still, but think I have now
succeeded where I failed the first time, all those years ago. The
challenge of a multiband RX seems within reach now.
In my opinion it is a testament to the designers, using the careful
selection of parts that they did in 1981, that the Progressive
Receiver can still be duplicated with semiconductors some 28 years
- Looks like the next pair of band modules (20 & 30m) will run
about $30 each. I am thinking its more important to get the RX in an
enclosure at this point.
I am considering one of the Ten Tec or Circuit Specialists enclosures right now.
Also thinking about the AADE DFD2 digital dial which would appear to work nicely for a dual conversion, multiband RX.
But first I ordered the parts for five accessory boards I wanted to try
in this PR RX. Some I have built previous examples of for past projects.
These accessory boards include:
"Filter Switching with Diodes" for later addition of a 600Hz IF filter
(W1FB QRP Notebook), "A Switched Variable Selectivity Audio Filter"
(W1FB QRP Notebook), "An Audio Derived S Meter" (W1FB QRP
Notebook), "Tunable Notch Filter" (W1FB Design Notebook), and a 5 watt
audio power amplifier for speaker operation using the TDA2611A in a
cloned circuit from the Ten Tec 1253.
The S meter and audio filter boards have been prepared for components.
- "An Audio-Derived S-Meter" (p.57 W1FB QRP Notebook), and "A Switched
Variable Selectivity AF Filter" (p.67 W1FB QRP Notebook) were completed
and tested OK.
I ordered extra 2200pF poly caps for the AF filter and took the closest
ones. I also started matching of the appropriate resistors, but quickly
found it uneccessary as I had ordered some 1% units from Mouser
and they were all saying the same thing on my DVM.
Although I have not 'heard' the AF filter yet, I can plainly see the
bandwidth response of the different poles using Hamscope on the
PC, and it appears as it should.
The S meter driver circuit was tested using a junkbox S/RF meter.
Well "The Progressive" progresses.....
- I had constructed the TDA2611A 5w audio amp on a piece of RS perf board
last week. I am very pleased with its performance. The circuit from the
TT 1253 is almost identical to the example circuit provided in the
datasheet for the chip. This amplifier was tested by connecting it
between my Ten Tec rig running headphone volume and a 4 inch speaker. I
was worried about some 'motorboating', but none was observed - even
while only connected with 1 ft. plain jumper leads all over the place.
Although there is no heatsink used in the TT 1253, the chip did get
slightly warm in my circuit, so I elected to install a small aluminum
heatsink and not worry about it. I will install a 10k PCB mount
'leveling' pot between the AF AMP/Product Detector board and this audio
power amp for proper drive level. I like alot of audio with the washer,
dryer, and/or the furnace always running down here in 'The shack'.
This board does the job well for $4.20
- The"Tunable Notch Filter" (W1FB Design Notebook) was also assembled
on some RS perfboard then, but without success. I spent several days
playing around with and double-checking the circuit. I could never even
get a peep through it. I replaced the 747 chip, re-wired it, etc, but
Funny thing was this would be the simplest of all the boards in this RX - but was just not to be.
I later remembered another notch circuit was
somewhere in one of those old A.R.R.L books. I found it! Page 233 of
"QRP Classics" is a re-print of a
Jan '85 QST design using a RC-4136 Op Amp by Tom Desaulniers, K4VIZ. "Variable Notch Filter For Receivers".
After looking things over and determining the parts
were still available, I proceeded to order the items and construct it.
Although it did not specify, I elected to use a matched pair of
.0022 uF polystyrene caps left over from the active audio filter
along with 1%, 10k resistors.
For testing I connected the input to the headphone jack of my rig at
low volume and the output to a PC running "Hamscope". It worked great
the first time!
For about $6 this would be a fun thing to have on the front panel of this 'Progressive'.
The notch control was
smooth as I watched it sweep across the audio spectrum. With the notch
control pot parked at either stop the notch is out of the audio
passband of the Ten Tec rig (And my ear). Below is a screenshot from
The notch on the right at 2000 Hz is from the Ten Tec rig's variable
notch filter for comparison. The homebrew notch circuit is set at about
1000 Hz on the left.
- I have also been working intermittently on salvaging some aluminum
sheet for an enclosure. I had considered the very nice Ten Tec and
Webtronics enclosures, but am going to try and give this route a go as
the price is not $40 or $50 and will probably be loosing my
There was a pair of obsolete airborne radio
telephone units in the electronics recycling pile at work. These boxes
were outdated and useless with current airborne radiotelephone systems
technology, but still had some very serious looking boards in them.
Anyways I figured I would try and use what is available first and
recycle that aluminum into this project. Maybe a bit like the 'cake
pan' rigs from the depression. So there is some metal work to be done.
I should end up about the same size as the largest Ten Tec enclosure.
Will be a H frame / clam shell type of box for maintenance access top
and bottom. Think its going to be tricky getting everything in there,
but we'll see.
One circuit board left to go, the filter switching board....
- Well there has been a lot of metal work going on, along with some
head scratching on trying to get the whole Progressive RX in a
modest-sized homebrew enclosure. There are a few extra 'goodies' in
this PR that add to the space requirements.
It ain't done yet, but think I have arrivied on a
suitable layout that will allow for 5 dual conversion bands (Total 6
band RX). Here are some preliminary layout pics of the top and bottom
of the enclosure made from the salvaged aluminum. I used these pictures
as a reference for further fit and assembly process.
The bottom half components have nearly all been
mounted since these pictures - excepting a small speaker and terminal
strip for DC distribution. A small front panel speaker and front panel
headphone jack were goals in this project. I was able to center both
the VFO and the frequency display which I think will look a bit nicer
in the end. The VFO and BFO are covered in boxes bent up from
galvanized heating duct material. Next will be mounting the front and
rear panel items.
For about $16, Ace Hardware had a pair of .025"
aluminum 8"X24" sheets that I bent up for the top and bottom 'clam
shell' covers. Admittedly this material is a bit thin for a large
enclosure - but will do the job fine for desktop use and this design
will provide good access top and bottom. I selected plastic
license plate anchor nuts from the hardware store for fastening the
clam shell halves to the H chassis. So for the cost of the clamshell
aluminum, plus some screws and rivets, I am saving a few bucks on the
It looks like the DFD2 digital dial would work well
with this type of RX and that is what I am planning for at this point.
This is a fun part of the project.
- OK I finally completed the "Filter Switching With Diodes" board from
p.132 of the W1FB QRP Design Notebook in between mounting boards and
metal working. For testing this board I used two DVM's. One in series
with the power supply to monitor the current draw as I was concerned
about this and any heat build up. The other I used to measure the
resistance through 'most' of the switching circuitry. (I would not be
able to measure DC throught the .01uF coupling caps at the input and
output - so tested next to them at the diodes.)
No smoke, and no heat that I could feel while
drawing about 40ma at 12.0v. The resistance through the filter circuits
were 30 and 70 ohms turned "On" , and about 3000 ohms with them turned
"Off". I think is a good board check, but remain concerned about any
signal loss through these diode switches.
Was not sure if it was neccessary, but installed
some tin shielding across the center of this board to aid
- Below are some pics of the components all mounted up to the enclosure. It will be time to start wiring things up then.
This bottom view is where most of the basic RX is. I
have small boxes made from thin gauge galvanized heating duct that fit
over the VFO and BFO compartments. They are removed for this show and
tell - as there is plenty of wiring to do now.
I had originally planned on only using a single
vernier reduction drive (6:1) on the VFO, but realized later that with
a VFO tuning range of 500Khz this would be pretty coarse tuning. Oops.
Looks like K5IRK used a two speed
on his - I forgot about this detail. So I ended up cascading a pair of
6:1 drives and am figuring that should be a nicer tuning rate of around
24 Khz per turn. I left room for adding a 600Hz INRAD experimental
filter kit down the road.
- On the top half of the chassis I put the BFO for some better
isolation as K5IRK did - along with the first mixer. All the converter
oscillators and input filters will go in up here. There is room for 5
sets of boards - so should end up with a 6 band Progressive RX. I read about one
guys's idea of mounting boards vertically in "QRP Classics". He used
spade type crimp connectors bent 90 degrees and drilled for the screw,
then soldered directly to the copper boards. This worked nicely for the
oscillator and filter boards. It also made sense to install the band
switch up there too.
I am waiting for Xmas to order a DFD2 display. I was concerned about it
working properly with this RX since its BOTH a dual and single
conversion RX depending which band, but I did the math for the DFD2 RF
formula, and loosing the converter oscillator signals for 80m operation
should still result in the proper operating frequency being displayed without having to switch a jumper..
- I fell into a couple of old habits on the front panel. The S
meter is the same type I used when building the Sierra. I really like it
and just had to have it here again on this project.
Also used a technique with a 60mm fan guard and a
double layer of aluminum window screen over the small speaker as I did
on a previous OHR 100A kit.. I wanted a 3" speaker but just could not
engineer that - so settled on a 2.5" one. I think I still met my
original requirement though.
Its going to be wiring time for awhile and hopefully Santa will bring a freq display next month.
I have the boards and some of the parts for the next 2 bands, 30 and 20m ....so there is still some more to come.
- A.A.D.E. DFD2 digital display has been ordered. Remaining items for 20 and 30m band options also ordered.
- I have just completed the matching enclosure for a companion
multiband transmitter. I hope to begin construction on that after
getting this Progressive RX working on 80 thru 20m. The TX enclosure
had to be completed before I lost access to the bending brake.
- The band switch was 'pre-wired' before installation in the front panel with RG-174U. Very busy little unit, pic below.
- The 80/40m RX is now wired 'in the box'. Unfortunately I didn't say
it was working in the box. Only some hums, pops, shrieks, etc. at this
time. I only just finished the wiring this AM. and there is a lot of
opportunity for wiring errors here. I will probably bypass the filter
switch to start troubleshooting since this was only tested with an
ohmmeter and not in the RX circuit, then maybe bypass the band switch
The RX is fused on the back with a 2A in
the holder. So the good news is no smoke and the fuse is holding.
I really don't want to let any of that smoke out of those parts.
Getting the whole RX into this small of a box was challenging for me
and I am hoping that the problem(s) is not too hard to find as access
and servicability were the tradeoffs in shoehorning it into this
smaller homebrew enclosure.
- I have decided to add a "Standby" switch on the lower left of the
front panel to mute the IF and AF boards - same as the "Mute" jack on
This way I can hopefully begin using the Progressive with my other tranceivers for TX'ing until the companion TX is built.
Now to get this thing working again before the DFD2 arrives....
- After present wrapping, could not resist going down to the shack and
take a peek at the RX. A little preliminary poking around I realized
that I figured wrong on the external speaker jack logic. One of the
pins on the external speaker jack was shorting out the audio. I saw the
mistake in my notes and corrected it. (There are 9 pins on these
Philmore closed circuit stereo jacks with no schematic provided). OK so
now I had SOME audio.
When tuning around I could come across CW - but it
sounded like modulated static. Also AM came in very nice. Somthing told
me to check the BFO then.
The BFO was not BFO'ing with a counter on it. After some digging around
found I had carelessly applied identification tape over the far end of
the BFO output shunt lead that would later go to the DFD2
display. The ground and center were shorted together under the tape.
It was re- taped and I was instantly rewarded with signals on 80 and
40m. A quick check of the VFO installed freq range was terrific.
The only problem I have left now is no signal at all
with the audio filter switched into the circuit with any number of
poles. The RX is only working in the the audio filter bypass position.
I can deal with that next no problem.
What a Christmas present.
- The DFD2 display kit arrived a few days ago. Unfortunately it was
missing some parts - so could not continue construction of it. Neil at
AADE said he would send out the missing components right away. I took
advantage of that time by testing the S meter circuit - which did not
work. There was not enough audio driving power for the S meter board,
even at full volume off of the last transistor of the
Progressive's audio board. I confirmed this by experiencing normal S
meter operation when drivin by the audio PA. I was partial to audio
derived S meters since allows helping me center signals in the audio
So I built a minimum part count LM386 audio amp to
drive the S meter board. I had to do this before a few years back when
adding the same S meter circuit to a OHR rig. The input to this LM386
board is the last transistor of the Progressive's AF board.
- Today the missing parts arrived for the DFD2, so this evening I
completed it, and am happy to report all is well. I was able to jumper
both configuration headers so that the display reads properly in single
AND dual conversion modes. This was a bit of a relief. I
still have to calibrate it, but is pretty close for now.
I need to find out more about where to set the BFO
frequency at. 700 off, 1500 off? I know its frequency must be selected
so the audio remains centered in the IF filter(s) passband. Alot of
conflicting info on this so far. I will probably begin work on the
input filters for 20 and 30m next before moving on to installing the
DFD2 in the front panel next week. Picture of the DFD2 during testing
- OK its in the box now. The input filters for 20 and 30m are built but
not aligned yet. The oscillators for 20 and 30m are built and peaked.
There is an interesting issue with the DFD2 in that
it displays USB so far on 80 and 40m when the BFO is adjusted for clear
speech. Its my understanding that 80 and 40m were LSB bands (Mostly).
Will see what happens with the displayed sideband on 20m when I get
- Next will be another peaking / alignment in the box of the basic 80m RX, then proceeding to align 40, 30, and 20m as well.
Final pictures at that time.
- Well everything is installed and aligned. It is fun to peak the rig.
I noticed that on 20m I had the same 'reversal' problem with the DFD2
sideband displaying LSB when the BFO was adjusted for clear speech. I
sent a note to AADE and Neil said that was unusual but sent a me a
different PIC to install in my DFD2 at no charge. All is well now.
- I have made a few QSO's with the Progressive on the air as a seperate
and it is really enjoyable and fun to operate. Short of calibrating the
DFD2 that is going to be about it on this project until after I work
out a matching TX for it.
There is a second video
of this project now over on YouTube.
This receiver was a big deal to me and it never would have made it to
completion without the help and encouragement of designers Lawson and
Some final pictures are below.
AA3SJ Progressive Receiver Pages with some
additions and modifications by W3TS
Crystal Sets to Sideband, A Guide to Building Your Own Amateur Radio
Station, By Frank Harris, K0IYE
(Chapter 13 deals with Mr. Harris' construction of a receiver using
"The Progressive Receiver" design as his basis.