Ham Radio Page
- Category: Ham Radio
- Created: Sunday, 28 October 2007 00:07
- Last Updated: Friday, 15 July 2022 12:07
- Written by Rick Swenton
- Hits: 16695
Over a half century
Click Here to see the WR1ABM Avon Repeater Photo Gallery from the mid 1970's.
WA1LMV/R Tower with me at the 60 ft. level. Picture at right.
I am a licensed Amateur Radio Operator (Advanced Class License) and repeater builder. I was first licensed as WN1LMV as a novice in 1969 at 16 years old. I currently hold an Advanced Class License. Prior to 2018 my previous call was WA1LMV. I am a retired IT professional having held technical and management positions with Kodak, Sun Microsystems and Oracle.
I am not a DXer, contester or a fan of CW. I am mainly a builder and experimenter. As a novice I built my first transmitter. It was a simple 15 watt CW transmitter using a 6L6 as a colpitts oscillator and surplus WW2 FT-243 crystal on 40 meters. It was built on a Bud aluminum chassis with a transformer and filter capacitor from an old TV. I later modified the tank circuit to work on 15 meters.
In the mid 1970s, I gravitated toward things digital starting with mechanical Teletype machines using them for RTTY. My first Teletype was a Model 15 [Model 15 You Tube Video] using a homemade vacuum tube terminal unit with a mercury wetted relay. Later I built a home-made ST-6 terminal unit and upgraded to Model 28 ASR and 35 ASR machines. I had the special service tools and was pretty good at repairing all kinds of problems. [Model 35 You Tube Video] My Teletype experience led me to volunteering for a period of time at the American School for the Deaf. Back in the '70s and '80s the Teletypes were used with modems so the deaf could communicate from home using their phone lines.
I have built and operated several VHF and UHF repeater systems throughout central Connecticut. In 1974 I was recruited into the technical committee of the Insurance City Repeater Club. There I was responsible for the vacuum tube to solid state upgrade of the WR1ABM repeater on 28/88 in Avon CT, the installation of the Avon UHF repeater, and the installation of the WR1AFU repeater and 6 meter remote base in Burlington CT. One of our club members owned a two-way radio business. He was very generous, supporting the club with donations of equipment and loaning of service tools. My affiliation with him gained me service experience on a wide variety of commercial radio equipment from Motorola, GE and RCA and later with Kenwood NXDN.
I was one of the 6 Meter repeater pioneers in Connecticut with WR1AIB on 52.01 / 53.01 in Burlington in 1978. I designed and built an array of repeater controllers for the repeater club and my own repeater using discrete TTL logic. Later in the 1990s I designed and built the hardware and wrote the software for an 8085 based repeater controller. It controlled my repeater until it was decommissioned in 2003. I wrote the microprocessor software myself which consisted of 140 pages of Z80 assembly language instructions. [source code]
I built my first home computer from scratch in 1978. It was based on the 8080 using a Model 35 ASR Teletype as the console. No CRT. Program storage and loading was done on the Teletype using paper tape. The computer was a hand-wired 8080 8-bit CPU running at 2 MHz (not GHz!). It had 16k of EPROM storage using eight 2716 2k x 8-bit chips and 2k of memory using two 2114 2k x 4-bit chips. I loaded into EPROM a crude operating system with an editor and assembler I copied from books. In 1983 I purchased a HealthKit H89 computer and became an H89 and CP/M expert authoring many magazine articles through the 1990s. Today I use Raspberry Pi and Arduino boards for my projects. I have been deeply involved with Home Automation since the mid 1980s.
My Home Automation web page is here: https://www.swenton.com/home-automation.
I am active on the Low Bands from home on AM, SSB and FT8. I operate on all bands from home and mobile on 6m, 2m, 220 MHz and 440 MHz on FM, DMR, DStar and NXDN. 440 MHz is limited because of the Air Force Base Pave Paws Radar on Cape Cod. I enjoy Ham, Shortwave, AM Broadcast Band listening and Longwave Beacon hunting with my SDRPlay RSPdx and RSP2 receivers. For the Low Bands my main rig is an Apache Labs ANAN-7000DLE MK-II SDR transceiver. I use Thetis for control of the transceiver. To compliment the ANAN, I use an Ameritron ALS-1306 1200-watt solid state FET amplifier.
I operate mobile on 2m and 440 MHz using FM and DMR.
My Ham Radio pages are here: https://www.swenton.com/w1rhs
I also have a General Mobile Radio Service (GMRS) license - WQZQ564
In 2020, I renovated my radio room/workshop and updated again in 2021. My rescue dog, Gracie, lives under my desk. It was her choice. Yes, that is an original Civil Defense logo on the wall. As a young ham radio operator. I was affiliated with the local Civil Defense, Red Cross and the Civil Air Patrol. I was certified in fallout shelter management and radiological monitoring. Back then, we thought it was possible to survive a nuclear war. We could ... for about a week or two.
• Apache Labs ANAN-7000DLE MKII SDR Transceiver 160-6m with Behringer CMD PL-1 Midi Controller
• Ameritron ALS-1306 1200 watt Solid State FET Amplifier 160-6m
• LDG AT-1000PROII Autotuner 160-6m
• Electro-Voice RE-27 N/D Studio Microphone
• ICOM IC-7300 SDR Transceiver 160-6m
• Xiegu G90 SDR Transceiver 160-10m
• Connect Systems CS-800D VHF/UHF analog/DMR digital with BFD Large Front Panel Screen
• TYT MD-9600 VHF/UHF analog/DMR digital with OpenGD77 Firmware (Alpha Tester)
• Yaesu FT-8900R Quad-Band 10, 6, 2, 440 VHF/UHF analog FM
• BTECH UV-25X4 Tri-Band 2, 220, 440 VHF/UHF analog FM
• SDR Play RSP2 and RSPdx SDR Wideband Receivers
• RTL-SDR v3 Wideband SDR Receiver Dongles
• Anytone AT-D878UV VHF/UHF DMR digital and analog FM handheld
converted from 868 (v2 board) and added Bluetooth
• Radioddity GD-77 VHF/UHF DMR digital and analog FM handheld with OpenGD77 firmware
• ICOM T90 Tri-Band 6, 2, 440 VHF/UHF analog FM handheld
• BTech UV-5X3 Tri-Band 2, 220, 440 VHF/UHF analog FM handheld
• Motorola PT-300 vintage Low Band 6m VHF analog FM portable
DIGITAL HOTSPOTS AND ANALOG NODES
• High Performance Hotspot STM32-DV MMDVM Controller on Raspberry Pi
with Pi-Star with Motorola CDM-1550 UHF transceiver, 1 to 30 watts
• MMDVM Simplex and Duplex HATs on Raspberry Pi with Pi-Star
• DVMega Dual Band HATs on Raspberry Pi with Pi-Star
• DVMega Dual Band on BlueDV (Blue Stack) for Windows, Android and Raspberry Pi
• ZumSpot-USB UHF dongle for Windows, Android and Raspberry Pi
• BlueDV AMBE Server for Windows with Northwest Digital ThumbDV AMBE3000 Vocoder
• BlueDV AMBE Server for Raspberry Pi with Northwest Digital ThumbDV AMBE3000 Vocoder
• ZUMRadio AMBE Server (stand-alone board)
• OpenGD77 using Radioddity GD-77 or TYT MD-9600 in Hotspot Mode
• Allstar SHARI UHF Node
• Thetis for the ANAN-7000
• SDR Console for the ANAN-7000, SDRPlay and RTL-SDR Receivers
• SDRUno for the SDRPlay Receivers and RTL-SDR Receivers
• SDR# for the RTL-SDR Receiver
• Win4ICOM Suite for the ICOM 7300
• Ham Radio Deluxe for CAT Control and HF digital modes
• WSJT-X for HF digital modes
• FLDIGI for HF digital modes
• WSJT-X for HF digital modes
• MULTIPSK for HF digital modes
• BlueDV for radio-less DMR, DSTAR, and YSF on Windows or Android.
ANTENNAS (limited space)
• 80m - 10m Off Center Fed dipole
• 160m - 10m end-fed longwire with counterpoise and 9:1 Unun
• Discones for VHF/UHF
• Ground Planes for VHF/UHF
Wide-angle view of the station after the renovation in 2020 and upgrades in 2021.
Operating from Cape Cod on the low bands, mostly on 75 Meter AM.
Lonely Guys Net Member #485 Saturday mornings on 3875 KHz.
For VHF/UHF Analog and Digital Modes see below. My DMR ID is 3109921. Allstar Node is 522710.
|Location||Frequencies In/Out||Mode||Talk Group|
|Bristol CT||443.875 MHz / 448.875 MHz
Brandmeister, Color Code 1, Time Slot 2
I operate on this repeater with a hotspot.
This is my primary hangout.
|Bristol CT||145.14 MHz / 144.54 MHz
I operate on this repeater using a computer.
|Barnstable MA||52.01 MHz / 53.01 MHz Tone 173.8 Hz.||FM|
|Barnstable MA||146.73 / 146.13 MHz Tone 67 Hz.||FM|
|Dennis MA||146.955 / 146.355 MHz Tone 88.5 Hz.
|Dennis MA||144.97 MHz / 146.46 MHz
DMR-MARC, Color Code 11, Time Slot 2
|Harwich MA||224.34 / 222.74 MHz Tone 100.0 Hz.||FM|
|Harwich MA||145.27 / 144.67 MHz Tone 67.0 Hz.||FM|
|Truro MA||147.255 / 147.855 MHz Tone 67 Hz.
Echolink 403358 Allstar Node 532900
|Digital Radio Networks|
|CDRA||Connecticut Digital Repeater Assn.on Brandmeister||DMR||31094|
|OpenGD77||The OpenGD77 on Brandmeister||DMR||98977|
|BARC||Barnstable Amateur Radio Club on Brandmeister||DMR||3130258|
|STEM||North Star Digital Net on Brandmeister||DMR||31630|
|NEDECN||DMR-MARC Repeaters in Bourne, Dennis and Eastham MA||DMR||8804 CapeNet|
|HS Hotline||Hamshack Hotline VoIP Phone||Ext||14577|
Member of the Barnstable Amateur Radio Club and the Pilgrim Amateur Radio Club on Cape Cod.
Member of the New England Digital Emergency Communications Network.
My current mobile installation on 6M, 2M, 220 and 440 MHz FM and 2M and 440 MHz DMR. Unfortunately, 440 MHz repeaters are mostly not allowed on Cape Cod because of the Pave Paws Air Force Radar System at Otis Air Force Base. My installation includes a mobile DMR hotspot. I remotely mounted the hotspot display under the radio control head.
I have been using DMR for many years, but I was first on NXDN because of my affiliation with a two-way radio shop and access to the equipment. Evans Mitchel, KD4EFM and I established the first NXDN internet contact between two NXDN repeaters, K1IFF/R in Connecticut and N4KEG/R in Florida back in 2012. This was before the NXCore and NXRef reflectors were available. It was a direct link between the two repeater routers over VPN.
I was one of the original alpha testers and am currently a beta tester for the OpenGD77 firmware for the Radioddity GD-77, Baofeng DM-1801 and RD5R DMR Radios. I am also an alpha tester of the OpenGD77 firmware for the TYT MD-9600.
I can operate the ANAN-7000 by remote control. Summer is the perfect time to make some contacts while relaxing on the deck. Protocol 2 requires 1 gigabit network speeds. My router and Wifi access points can keep up fine when operating remotely. I use a bluetooth music speaker so I can get fairly good high fidelity sound. Here, I am using a small computer electret condenser mic. I also have a large diaphrgam studio condenser mic with a USB adapter for portable use. Mic and speaker audio are sent over the network using the virtual audio cable support in the Thetis control software. All of the radio's controls are available on the laptop.
Gracie is my rescue dog from Arkansas. She sleeps in her favorite place under my desk. She never barks or otherwise interrupts the important radio transmissions emanating from this station.
I was a Repeater Builder in the Hartford CT area from 1974 through 2003. I was responsible for the tube to solid-state transition of the WR1ABM 28/88 repeater in Avon CT, adding a solid-state UHF RCA 1000 series repeater and adding a new VHF repeater with 6-meter Remote Base, WR1AFU 75/15 in Burlington CT back in the late 1970s through 1980s for the Insurance City Repeater Club. From 1978 to 2003 I had my own repeater, WA1LMV/R, formerly WR1AIB, simulcasting on 447.925 MHz and 53.01 MHz also in Burlington, CT.
In those days we had access to RCA land mobile radios. Our repeaters were built from RCA Series 700, 1000 (left, middle) and Veetac radios (right.) I had some older RCA mobile radios in my car. I had Supercarphone and Superfleetphone models. The Supercarphone had directly heated cathodes in the tube finals. The tubes heated instantly when you lifted the mic from the cradle. The latter was all solid state, but the UHF model used a varactor tripler. 45 watts from the VHF final transistors yielded 15 watts from the varactor. These models were power hungry requiring thick cables from the battery to the trunk. The RCA radios were easy to modify. There were no edge connectors. The circuit boards were interconnected point-to-point with pins on the boards and push-on wire connectors. It was easy to tap into things like COS, TOS and PTT lines.
My own 6 Meter / UHF repeater, originally WR1AIB and later WA1LMV/R, went on the air in Burlington CT on 52.01/53.01 and 442.925/447.925 in 1978 and was decomissioned in 2003. The first 6-meter repeater was built using a GE Master Executive shown above. These radios were obtained after the local police department converted from Low Band to 800 mHz. The second 6-meter repeater was built using an RCA 1000 Series. The UHF repeater was built from an RCA Veetac. You can learn quite a bit about operating a repeater by running one on 6 Meters. There are challenges with desense and tower noise that are much worse on 6 Meters than on the upper bands. Let's not overlook the additional RFI related to electric fences on the farm. I am so grateful to my friend, Don, K1ZSG, for sponsoring the site, power, tower and most of the equipment for all those years.
I operated my own dual band repeater system between 1977 and 2003 in Burlington, CT.
On the air in 1978 as WR1AIB.
52.01 MHz. In / 53.01 MHz. Out
162.2 Hz. tone
442.925 MHz. In / 447.925 MHz. Out
110.9 Hz. tone
This repeater used a personally designed and built 8085 controller. The hardware and software is full-featured. The controller supports speech, accessories, time scheduling, autopatch with speed dialing, radio and landline control, remote bases, diagnostics, video display terminal, and much more. I could even turn on the flood lights at the repeater site while driving in.
I wrote the 140 page software program in Z80 assembly language. It assembles down to a 17k machine language program in EPROM. The software is a full-blown real time operating system with 5 hardware interrupt levels to simultaneously process DTMF commands from the receivers, DTMF commands from the phone line, buffered type-ahead commands from the terminal keyboard, background timer processing interrupt, real-time error trapping (boundary checking for program counter and stack pointer) and a fail-safe heartbeat interrupt. It had Autopatch and Reverse Autopatch.
Here is the source code in case you are interested.
Here's the User's Manual.
Here are the features in detail:
- Two main receiver inputs for COS and PL
- Two aux receiver inputs for COS
- Audio gate control outputs to control the mixer gates
- Two main transmitter outputs
- Two aux transmitter outputs
- MCW messages and ID with programmable speed and pitch
- ID Timer with polite ID and broadcast ID
- Phoenemic based speech synthesizer with unlimited vocabulary
- Separate main receiver time-out timers with PL override
- Separate main and aux receiver timers for access and release delays
- Aux transmitters inactivity dump timers
- Autopatch with inactivity dump timer
- DTMF regeneration and speed dialer with speech readout
- DTMF mute of audio gates
- Reverse autopatch with announce
- Dial-in landline system control
- Courtesy tones with programmable MCW character and pitch
- Aux receiver and transmitter status tones
- CRT console with command line, menu and status display
- Full control over any input or output
- Interrupt driven background timing system
- Foreground priority based task driven master processor
- Two interrupt driven DTMF decoders with buffered type-ahead
- Interrupt driven terminal type-ahead buffer
- Watchdog timer / fail-safe processor in hardware and software
- Time of Day alarm clock / calendar with hourly chime, speech readout and event scheduling
- Programmable macro commands for speed key commands.
- Direct memory access through console or DTMF with speech readout
- Remote base synthesizer control with programmable frequency banks, mode and power control
- Detects presence of speech and clock chips and emulates functionality in software if not detected
During the winter of 2003, the tower guy wires were hit by a tree branch that had fallen during an ice storm. The guy wire broke and the tower came down. Fortunately nobody, including the residents of the associated house were injured. The tower fell in an optimal direction. Now it's time to clean house at the site to make way for paying customers.
Thanks to my friend Don Nelson, K1ZSG, for his assistance and generosity for all these years.
Repeater Microprocessor Controller
Here is the top view of the controller. It is a surplus single-board 8085 based computer with a 5 Mhz clock. It was removed from a Kodak Ektachem Blood Analyzer during a modification. The board can accept an 8K, 16K or 32K EPROM and has four memory-mapped 8-bit output ports and three memory-mapped 8-bit input ports (not including the I/O ports on the PPI) along with 4K of Static Ram. In order for me to use this board, I had to learn how to program the 8253 Programmable Interval Timer (PIT), the 8255 Programmable Peripheral Interface (PPI), the 8259 Programmable Interrupt Controller (PIC), and the 8251 Universal Synchronous/Asynchronous Receiver-Transmitter (USART). Learning how to initialize those and program to work with this board was no trivial task. Above the main board is a custom I/O expansion board with a time-of-day clock with battery backup, an SSI-202 touchtone decoder, an SSI-75T2089 touchtone encoder/decoder, a watchdog timer, a tone generator, an SSI-263 speech generator and several I/O ports. I had to learn how to program the SSI-263 phoneme-based speech synthesizer which speaks words and phrases by combining phoneme sounds.
On the back edge of the cabinet there is a small analog-to-TTL input board. This board has transistor arrays in 14 pin DIP packages, pull-up resistors, inverters and DIP switches. This is a universal receiver to controller interface. Each input is a 0 to 15v input which produces a 0 to 5v TTL signal. The DIP switches can program an inverted signal polarity. This is used to connect the receivers' COS, TOS and other signals to the controller.
This is the inside view. The 8085 CPU board was salvaged from a Kodak Blood Analyzer. I re-programmed the board from scratch adding hardware on the proto board that included a speech synthesizer, time of day clock, two DTMF decoders, a DTMF encoder, battery backup, watchdog timer, baud rate generator and more. On the CPU board I had to learn how to program the Intel 8080 series of support chips such as the 8255 Programmable Peripheral Interface, the 8253 Programmable Interval Timer, the 8259 Programmable Interrupt Controller, the 8251 Universal Synchronous Receiver-Transmitter and then learn how to program the SSI263 Speech Synthesizer on the proto board. The speech had unlimited vocabulary because it was programmed using phonemes. I had to "teach" the speech synthesizer every word by stringing phonetic sounds and then add volume, duration and pitch inflections. I wrote the software in Z80 Assembly Language using only the Z80 instructions that had equivalents in 8080/8085 Assembly Language. I wrote the software using a HealthKit H89 computer and programmed the controller using a homemade EPROM programmer. I built an Ultraviolet EPROM eraser using a bathroom germicide UV lamp and a small florescent ballast salvaged from an old desk lamp.
In order to easily interface to the main board I soldered a 28 pin DIP socket to the top of the static RAM chip. This gave me address, data and control lines that I could bring to the expansion board with a ribbon cable.
The power supply was a simple analog supply with a 5v regulator. The power cord receptacle was an EMI filter with exposed solder lugs. I coated the lugs with black RTV for shock protection. Apparently, I was not worried about the connections on the fuse.
Some things could not be totally solid-state. The only relay was for telephone line access.
Besides the power supply transformer there was one other transformer, a 600 ohm one to interface to the telephone line.
Here's the front panel. Power switch, power indicator, touchtone pad and reset button.
Finally here's a picture of the expansion I/O board. Notice the 28 pin DIP socket in the lower right. That's where the ribbon cable plugs in and connects to the corresponding socket on the CPU board. The variable capacitor on the right was to trim the watch crystal for the time-of-day clock. The 1.8432 MHz crystal was for the baud rate generator for RS232 serial communication. The crystal near the rechargeable battery is a 3.579 MHz color burst crystal for the touch tone encoder/decoder chips.
Here are a few pictures of the decommissioned equipment arriving at my house along with some old pictures of when the system was in service.
Two 20 AMP power supplies (left) under the keyboard, the ADDS 2020 CRT monitor (center), the RCA Series 1000 Low Band Transceiver below the CRT, and the microprocessor controller and audio mixer (right).
Controller (top) and mixer (bottom).
Top View of the heap.
A "pre-micro controller" picture of the rack sometime around 1990. At the top is a custom antenna rotator controller that runs an Aliance U100 motor. It takes commands from the logic system and can position the motor from 0 to 360 degrees in 10 degree increments. Next is a rack mount RCA SuperFleetfone low band receiver followed by the 16 channel audio mixer. This custom designed audio mixer actually contained the receiver squelch gates which were solid state switch ICs.
Before the microprocessor controller, there were 15 logic boards controlling the system. From top to bottom: The 16 channel custom audio mixer, two banks of 5 logic boards. The first 5 are the repeater logic, the second 5 are the control system. A bank of 5 more boards in the white panel were expansion functions. The binding posts above the main logic rack are +5V and GND for the Logic Pen. (Remember those?) I had a board extender so I could operate each board extended out of its slot for troubleshooting.
The older system had a Teltone 3-board DTMF decoder and a Wescom Hybrid for the Autopatch. Below that is the two meter remote base consisting of a Standard HT transceiver board and a GLB Synthesizer interfaced to the repeater logic. Last is the GE MASTR Royal Exec transceiver, the original 6 Meter repeater receiver and transmitter for 52.01 / 53.01 MHz.
Development of the new controller hardware. The controller could accept control input simultaneously from the CRT keyboard, two radio receivers and the phone line. Software was written on the Heathkit H89 computer in Z80 Assembly Language. The 140 page program assembled down to 17 kilobytes to fit in an EEPROM. I built an EEPROM programmer to work with the H89 computer. I built an EEPROM eraser using an ultraviolet bulb intended for a bathroom germicide device. These bulbs look like florescent bulbs but with a clear glass envelope. There's no white frosting on the inside.
Inside view of the controller. The computer board (the lower one) is a control board from a Kodak blood analyzer. It has an 8085 µP running at 5 MHz, up to 64K of EPROM and plenty of I/O ports. The upper board is the additional circuits that add two DTMF decoders, a DTMF encoder, speech synthesizer, time of day clock, watchdog timer and audio tone circuits.
View of the controller under construction. Notice the Icom IC-4AT handheld radio and the ADDS Viewpoint terminal on the right.
Screen shot of the video display from Feb. 23, 1991. Notice the single letter control command menu, the display of the various timers, and the display of the I/O port signals shown as ones or zeros. When the controller was running, this screen provided a real-time display of the various signals. The ID Timer, receiver Time Out Timers, the Transmit tail timer and date and time all showed updating on the screen. The ones and zeros on the right side reflect the various signals like receiver COS, TOS, PTT and more. Each set of signals had two rows. The top row is the control bits. The bottom row is the status bits. The status bits come on and off as the inputs change or as the controller changes output bits. However, the signal will only be processed if the control bit above the status bit is set by the control system. The control system can enable or disable any individual signal by changing the control bit. The display was an ordinary dumb serial terminal running at 19,200 baud. It looked like a video raster because I performed direct cursor addressing with the cursor display disabled.
Here's a blast from the past. This is my Ham Radio Shack as it appeared in 1973. Starting at the top left corner is a barely visible Heathkit Mohegan shortwave portable. Next is a Heathkit Signal Generator. The black panel with the six knobs is a stereo tube type homemade amplifier connected to the adjacent Scott FM tuner with a homemade stereo demodulator. On the middle shelf is a homemade oscilloscope and phone patch console, a low band 30-50 MHz tunable monitor, and a Glalaxy three channel cyrystal controlled 2M FM transceiver. On the bench is a National NC-76 Ham Band receiver. On the table on the right is a Polycom 6M AM transceiver, an SBE-33 Low Band SSB transceiver, A Halicrafters SX-99 Shortwave receiver and finally a Heathkit Marauder low band SSB transmitter. Under the bench visible behind the chair is a Collins 32V1 low band AM transmitter. Thank God my Dad was generous with the precious space in his small workshop!
Later I installed some of the equipment into a nice 19 inch rack cabinet/desk on the right. Notice the Heathkit electronic keyer and the mechanical 24-hour digital clockm set to GMT, of course. This was a nice station in its day. It was all used equipment when I got it. On the top shelf, L to R, is a Hallicrafters SX-99 shortwave receiver, a Heathkit Mohegan portable shortwave receiver and an SBE-33 80 through 10 meter SSB base/mobile transceiver. On top of the SBE-33 is a Polycom 6 six meter AM transceiver belonging to the city's Civil Defense. On the bottom shelf is a Trio receiver (before they changed the name to Kenwood) and a National NC-76 receiver.
This is the transmitter array with the Heathkit Maurader and the Collins 32V-1. The home-made oscilloscope and phone patch are at the top. An adjustable regulated power supply is at the bototm.
Well, well, well. When I was a member of the Bristol CT Civil Defense we operated a 6 meter AM net and I operated from the car. I used a Halo antenna mounted on the bumper of my prestigious 1967 Rambler American. I actually commuted to college and was seen in public with this car. Eventually by brother repaired the accident damage and repainted the car the same yellow color. During one summer I replaced the engine in this car at the high school auto shop with the help of the shop teacher.
Here's the workbench around 1978 along with my first dog, Brownie. You can see the Motorola signal generator on the top shelf and the Motorola service monitor on the bottom. By this time in my life I became rather proficient in servicing commercial two-way radio products. Around 1978 I assisted the local radio shop with the transition of the Bristol CT Police Dept. from Low Band (39.42 MHz) to 800 Mhz.