<PAGE>

                                   FORM 10-Q

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


(Mark One)
[x]   Quarterly report pursuant to Section 13 or 15(d) of the Securities
      Exchange Act of 1934
For the quarterly period ended September 30, 1999
                               ------------------

[ ]   Transition report pursuant to Section 13 or 15(d) of the Securities
      Exchange Act of 1934
For the transition period from              to
                              --------------  -----------

                       Commission File Number:  0-15714

                       JONES CABLE INCOME FUND 1-C, LTD.
--------------------------------------------------------------------------------
               Exact name of registrant as specified in charter

Colorado                                                              84-1010419
--------------------------------------------------------------------------------
State of organization                                     I.R.S. employer I.D. #

                            c/o Comcast Corporation
                1500 Market Street, Philadelphia, PA 19102-2148
                -----------------------------------------------
                     Address of principal executive office

                                (215) 665-1700
                         -----------------------------
                         Registrant's telephone number


Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

Yes    X                                                                No
     -----                                                                 -----
<PAGE>

                       JONES CABLE INCOME FUND 1-C, LTD.
                       ---------------------------------
                            (A Limited Partnership)

                     UNAUDITED CONSOLIDATED BALANCE SHEETS
                     -------------------------------------

<TABLE>
<CAPTION>
                                                                     September 30,   December 31,
               ASSETS                                                    1999            1998
               ------                                                -------------   ------------
<S>                                                                  <C>             <C>
CASH                                                                  $6,714,752     $   118,938

PROCEEDS FROM SALE IN INTEREST-BEARING ESCROW ACCOUNT                    503,750               -

TRADE RECEIVABLES, less allowance for doubtful
  receivables of $2,507 at December 31, 1998                                --             8,676

INVESTMENT IN CABLE TELEVISION PROPERTIES:
  Property, plant and equipment, at cost                                    --         5,763,293
  Less- accumulated depreciation                                            --        (3,331,334)
                                                                      ----------     -----------

                                                                            --         2,431,959

  Franchise costs and other intangible assets, net of accumulated
    amortization of $3,793,620 at December 31, 1998                         --           833,473
                                                                      ----------     -----------

        Total investment in cable television properties                     --         3,265,432
                                                                      ----------     -----------

DEPOSITS, PREPAID EXPENSES AND DEFERRED CHARGES                             --           450,504
                                                                      ----------     -----------

        Total assets                                                  $7,218,502     $ 3,843,550
                                                                      ==========     ===========
</TABLE>


     The accompanying notes to unaudited consolidated financial statements
      are an integral part of these unaudited consolidated balance sheets.


                                       2
<PAGE>

                       JONES CABLE INCOME FUND 1-C, LTD.
                       ---------------------------------
                            (A Limited Partnership)

                     UNAUDITED CONSOLIDATED BALANCE SHEETS
                     -------------------------------------
<TABLE>
<CAPTION>


                                                             September 30,   December 31,
    LIABILITIES AND PARTNERS' CAPITAL                             1999           1998
    ---------------------------------                        -------------   ------------
<S>                                                          <C>             <C>
LIABILITIES:
  Debt                                                        $       --     $  2,417,756
  Accounts payable and accrued liabilities                         407,833      1,287,365
  Subscriber prepayments                                              --           32,076
                                                              ------------   ------------

                  Total liabilities                                407,833      3,737,197
                                                              ------------   ------------

MINORITY INTEREST IN JOINT VENTURE                               2,750,185         83,879
                                                              ------------   ------------

PARTNERS' CAPITAL:
  General Partner-
    Contributed capital                                              1,000          1,000
    Accumulated earnings                                           112,443        112,443
    Distributions                                                 (113,443)      (113,443)
                                                              ------------   ------------
                                                                         -              -
                                                              ------------   ------------

  Limited Partners-
    Net contributed capital (85,059 units outstanding at
      September 30, 1999 and December 31, 1998)                 34,909,262     34,909,262
    Accumulated earnings                                        14,330,927     10,292,917
    Distributions                                              (45,179,705)   (45,179,705)
                                                              ------------   ------------

                                                                 4,060,484         22,474
                                                              ------------   ------------

                  Total liabilities and partners' capital     $  7,218,502   $  3,843,550
                                                              ============   ============
</TABLE>


     The accompanying notes to unaudited consolidated financial statements
     are an integral part of these unaudited consolidated balance sheets.


                                       3
<PAGE>

                       JONES CABLE INCOME FUND 1-C, LTD.
                       ---------------------------------
                            (A Limited Partnership)

                UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
                -----------------------------------------------
<TABLE>
<CAPTION>


                                                For the Three Months Ended        For the Nine Months Ended
                                                       September 30,                     September 30,
                                               ----------------------------      ----------------------------

                                                   1999             1998            1999             1998
                                               -----------      -----------      -----------     ------------
<S>                                            <C>           <C>                 <C>             <C>
REVENUES                                       $   188,993      $ 1,689,051      $ 1,384,006     $  7,935,981

COSTS AND EXPENSES:
  Operating expenses                               184,450        1,317,367          909,868        4,931,092
  Management fees and allocated overhead
    from General Partner                            17,843          186,371          146,326          883,373
  Depreciation and amortization                     64,186          572,488          461,230        2,745,937
                                               -----------      -----------      -----------     ------------

OPERATING LOSS                                     (77,486)        (387,175)        (133,418)        (624,421)
                                               -----------      -----------      -----------     ------------

OTHER INCOME (EXPENSE):
  Interest expense                                  (3,514)        (152,863)         (84,280)        (555,149)
  Interest income on escrowed proceeds               3,750                -            3,750                -
  Gain on sale of cable television systems       6,350,069       23,191,974        6,350,069       35,830,323
  Other, net                                        31,663           72,925          568,195          (20,643)
                                               -----------      -----------      -----------     ------------

          Total other income (expense), net      6,381,968       23,112,036        6,837,734       35,254,531
                                               -----------      -----------      -----------     ------------

CONSOLIDATED INCOME                              6,304,482       22,724,861        6,704,316       34,630,110

MINORITY INTEREST IN
  CONSOLIDATED INCOME                           (2,507,294)      (9,037,678)      (2,666,306)     (13,772,395)
                                               -----------      -----------      -----------     ------------

NET INCOME                                     $ 3,797,188      $13,687,183      $ 4,038,010     $ 20,857,715
                                               ===========      ===========      ===========     ============

ALLOCATION OF NET INCOME:
  General Partner                              $    (2,408)     $     4,415      $         -     $      6,448
                                               ===========      ===========      ===========     ============

  Limited Partners                             $ 3,799,596      $13,682,768      $ 4,038,010     $ 20,851,267
                                               ===========      ===========      ===========     ============

NET INCOME PER LIMITED
  PARTNERSHIP UNIT                             $     44.67      $    160.87      $     47.47     $     245.14
                                               ===========      ===========      ===========     ============

WEIGHTED AVERAGE NUMBER
  OF LIMITED PARTNERSHIP
  UNITS OUTSTANDING                                 85,059           85,059           85,059           85,059
                                               ===========      ===========      ===========     ============

</TABLE>


     The accompanying notes to unaudited consolidated financial statements
       are an integral part of these unaudited consolidated statements.

                                       4
<PAGE>

                       JONES CABLE INCOME FUND 1-C, LTD.
                       ---------------------------------
                            (A Limited Partnership)

                UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS
                -----------------------------------------------
<TABLE>
<CAPTION>

                                                                For the Nine Months Ended
                                                                       September 30,
                                                               ---------------------------
                                                                   1999           1998
                                                               ------------  --------------
<S>                                                            <C>           <C>

CASH FLOWS FROM OPERATING ACTIVITIES:
  Net income                                                   $ 4,038,010    $ 20,857,715
  Adjustments to reconcile net income to net cash
    provided by operating activities:
      Depreciation and amortization                                461,230       2,745,937
      Gain on sale of cable television systems                  (6,350,069)    (35,830,323)
      Minority interest in consolidated income                   2,666,306      13,772,395
      Decrease in trade receivables                                  8,676         357,060
      Decrease (increase) in deposits, prepaid expenses and
         deferred charges                                          413,166        (291,819)
      Decrease in accounts payable, accrued liabilities
         and subscriber prepayments                               (911,608)     (1,026,159)
                                                               -----------    ------------

          Net cash provided by operating activities                325,711         584,806
                                                               -----------    ------------

CASH FLOWS FROM INVESTING ACTIVITIES:
  Purchase of property and equipment, net                         (109,589)     (1,290,508)
  Proceeds from sale of cable television systems, net of
    brokerage fees and escrow                                    8,797,448      60,596,250
                                                               -----------    ------------

          Net cash provided by investing activities              8,687,859      59,305,742
                                                               -----------    ------------

CASH FLOWS FROM FINANCING ACTIVITIES:
  Proceeds from borrowings                                               -       1,339,584
  Repayment of debt                                             (2,417,756)    (22,042,598)
  Distribution to Joint Venture Partner                                  -     (15,700,281)
  Distribution to limited partners                                       -     (23,777,419)
                                                               -----------    ------------

          Net cash used in financing activities                 (2,417,756)    (60,180,714)
                                                               -----------    ------------

Increase (decrease) in cash                                      6,595,814        (290,166)

Cash, beginning of period                                          118,938         454,501
                                                               -----------    ------------

Cash, end of period                                            $ 6,714,752    $    164,335
                                                               ===========    ============

SUPPLEMENTAL CASH FLOW DISCLOSURE:
  Interest paid                                                $    84,684    $    790,430
                                                               ===========    ============

</TABLE>

     The accompanying notes to unaudited consolidated financial statements
        are an integral part of these unaudited consolidated statements.

                                       5
<PAGE>

                       JONES CABLE INCOME FUND 1-C, LTD.
                       ---------------------------------
                            (A Limited Partnership)

              NOTES TO UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS
              ----------------------------------------------------


(1)  This Form 10-Q is being filed in conformity with the SEC requirements for
unaudited financial statements and does not contain all of the necessary
footnote disclosures required for a complete presentation of the Balance Sheets
and Statements of Operations and Cash Flows in conformity with generally
accepted accounting principles. However, in the opinion of management, this data
includes all adjustments, consisting only of normal recurring accruals,
necessary to present fairly the financial position of Jones Cable Income Fund 1-
C, Ltd. (the "Partnership") at September 30, 1999 and December 31, 1998 and its
Statements of Operations for the three and nine month periods ended September
30, 1999 and 1998 and its Statements of Cash Flows for the nine month periods
ended September 30, 1999 and 1998.

     The accompanying consolidated financial statements include 100 percent of
the accounts of the Partnership and those of Jones Cable Income Fund 1-B/C
Venture (the "Venture") reduced by the 40 percent minority interest in the
Venture owned by Jones Cable Income Fund 1-B, Ltd. ("Fund 1-B").  All
interpartnership accounts and transactions have been eliminated.  The Venture
owned and operated the cable television system serving Myrtle Creek, Oregon (the
"Myrtle Creek System") until its sale on July 30, 1999.  Jones Intercable, Inc.,
a publicly held Colorado corporation, is the "General Partner" and manages the
Partnership and the Venture.

     On April 7, 1999, Comcast Corporation ("Comcast") completed the acquisition
of a controlling interest in the General Partner for aggregate consideration of
$706.3 million. Comcast acquired an additional 1.0 million shares of the General
Partner's Class A Common Stock on June 29, 1999 for $50.0 million in a private
transaction. Upon completion of these transactions, Comcast owns approximately
13.8 million shares of the General Partner's Class A Common Stock and
approximately 2.9 million shares of the General Partner's Common Stock,
representing 39.6% of the economic interest and 48.3% of the voting interest in
the General Partner. Comcast has contributed its shares in the General Partner
to its wholly owned subsidiary, Comcast Cable Communications, Inc. ("Comcast
Cable"). The approximately 2.9 million shares of Common Stock owned by Comcast
Cable represent shares having the right to elect approximately 75% of the Board
of Directors of the General Partner. The General Partner is now a consolidated
public company subsidiary of Comcast Cable.

     In connection with Comcast's acquisition of a controlling interest in the
General Partner on April 7, 1999, all of the persons who were executive officers
of the General Partner as of that date terminated their employment with the
General Partner. The General Partner's Board of Directors has elected new
executive officers, each of whom also is an officer of Comcast. As of July 7,
1999, all persons who were employed at the General Partner's former corporate
offices in Englewood, Colorado had terminated their employment with the General
Partner. The General Partner's corporate offices are now located at 1500 Market
Street, Philadelphia, Pennsylvania 19102-2148.

(2)  On July 30, 1999, the Venture sold the Myrtle Creek System to an
unaffiliated party for a sales price of $9,535,844, subject to customary closing
adjustments. The initial sales price of $10,000,000 was reduced $1,507 for each
of the Myrtle Creek System's equivalent basic subscribers less than 6,650 at
closing. At July 30, 1999, the Myrtle Creek System had 6,342 equivalent basic
subscribers, which reduced the initial sales price by $464,156. When final
closing adjustments are done approximately ninety days after closing, the
equivalent basic subscribers will be recounted and the sales price will be
adjusted accordingly. From the sale proceeds, the Venture paid a $238,396
brokerage fee to The Intercable Group, Ltd. ("The Intercable Group"), a
subsidiary of the General Partner, representing 2.5 percent of the sales price,
for acting as a broker in the transaction, repaid the outstanding balance on the
Venture's credit facility of $2,400,000, and deposited $500,000 into an
interest-bearing indemnity escrow account. The Venture will settle working
capital adjustments and, based upon

                                       6
<PAGE>

financial information as of September 30, 1999, the remaining net sale proceeds
will be distributed 60 percent to the Partnership and 40 percent to Fund 1-B.
The Partnership, in turn, will create a reserve to cover the administrative
expenses of the Partnership and then it plans to distribute the balance to the
limited partners of the Partnership. Because this distribution to the limited
partners of the Partnership together with all prior distributions will not
return the amount initially contributed by the limited partners to the
Partnership plus the limited partners' liquidation preference provided by the
Partnership's limited partnership agreement, the General Partner of the
Partnership will not receive a general partner distribution from the Myrtle
Creek System's sale proceeds.

     For a period of one year following the closing date, $500,000 of the sale
proceeds will remain in escrow as security for the Venture's agreement to
indemnify the purchaser under the asset purchase agreement.  The Venture's
primary exposure, if any, will relate to the representations and warranties made
about the Myrtle Creek System in the asset purchase agreement.  Any amounts
remaining from this indemnity escrow account and not claimed by the buyer at the
end of the one-year escrow period plus interest earned on the escrowed funds
will be returned to the Venture.  From this amount, the Venture will pay any
remaining liabilities and the Venture then plans to distribute the balance, if
any, to its partners.  From its share of this distribution, the Partnership will
retain funds necessary to cover the administrative expenses of the Partnership
and it plans to distribute the balance, if any, to the limited partners.

     Although the sale of the Myrtle Creek System represented the sale of the
only remaining operating asset of the Venture, and the Partnership's interest in
the Venture represents its only asset, the Venture and the Partnership will not
be dissolved until all proceeds from escrow have been distributed.

(3)  On January 9, 1998, the Venture sold the cable television system serving
Clearlake and Lakeport, California (the "Clearlake System") to an unaffiliated
party. The Venture repaid a portion of its indebtedness, settled working capital
adjustments, deposited $300,000 into an indemnity escrow account and distributed
the remaining net sale proceeds to the Partnership and Fund 1-B. The indemnity
escrow period expired on January 9, 1999, and all of the $300,000 indemnity
escrow amount plus $14,977 of interest was returned to the Venture. The Venture
has distributed these funds 60 percent to the Partnership and 40 percent to Fund
1-B. The Partnership used its portion of these proceeds to repay a portion of
its remaining liabilities, therefore no distribution of these funds was made to
the limited partners.

(4)  The General Partner manages the Partnership and the Venture and receives a
fee for its services equal to 5 percent of the gross revenues of the Venture,
excluding revenues from the sale of cable television systems or franchises. The
General Partner has not received and will not receive a management fee after
July 30, 1999. Management fees paid to the General Partner by the Venture for
the three and nine month periods ended September 30, 1999 were $9,449 and
$69,200, respectively, compared to $84,452 and $396,799, respectively, for the
similar 1998 periods.

     The Venture will continue to reimburse the General Partner for certain
administrative expenses.  These expenses represent the salaries and related
benefits paid for corporate personnel.  Such personnel provide administrative,
accounting, tax, legal and investor relations services to the Venture and its
constituent partnerships.  Such services, and their related costs, are necessary
to the administration of the Venture and its constituent partnerships until they
are dissolved.  Such costs were charged to operating costs during the periods
that the Venture operated its cable telvision systems.  Subsequent to the sale
of the Venture's final cable television system, such costs were charged to other
expense.  Reimbursements made to the Venture by the General Partner for overhead
and administrative expenses during the three and nine month periods ended
September 30, 1999 were $8,394 and $77,126, respectively, compared to $101,919
and $486,574, respectively, for the similar 1998 periods.

                                       7
<PAGE>

                       JONES CABLE INCOME FUND 1-C, LTD.
                       ---------------------------------
                            (A Limited Partnership)

        MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
        ---------------------------------------------------------------
                             RESULTS OF OPERATIONS
                             ---------------------

FINANCIAL CONDITION
-------------------

     The Partnership owns a 60 percent interest in the Venture and Fund 1-B owns
a 40 percent interest in the Venture.  The accompanying financial statements
include 100 percent of the accounts of the Partnership and those of the Venture
reduced by Fund 1-B's 40 percent minority interest in the Venture.

     On July 30, 1999, the Venture sold the Myrtle Creek System to an
unaffiliated party for a sales price of $9,535,844, subject to customary closing
adjustments. The initial sales price of $10,000,000 was reduced $1,507 for each
of the Myrtle Creek System's equivalent basic subscribers less than 6,650 at
closing. At July 30, 1999, the Myrtle Creek System had 6,342 equivalent basic
subscribers, which reduced the initial sales price by $464,156. When final
closing adjustments are done approximately ninety days after closing, the
equivalent basic subscribers will be recounted and the sales price will be
adjusted accordingly. From the sale proceeds, the Venture paid a $238,396
brokerage fee to The Intercable Group representing 2.5 percent of the sales
price, for acting as a broker in the transaction, repaid the outstanding balance
on the Venture's credit facility of $2,400,000, and deposited $500,000 into an
interest-bearing indemnity escrow account. The Venture will settle working
capital adjustments and, based upon financial information as of September 30,
1999, the remaining net sale proceeds will be distributed 60 percent to the
Partnership and 40 percent to Fund 1-B. The Partnership, in turn, will create a
reserve to cover the administrative expenses of the Partnership and then it
plans to distribute the balance to the limited partners of the Partnership.
Because this distribution to the limited partners of the Partnership together
with all prior distributions will not return the amount initially contributed by
the limited partners to the Partnership plus the limited partners' liquidation
preference provided by the Partnership's limited partnership agreement, the
General Partner of the Partnership will not receive a general partner
distribution from the Myrtle Creek System's sale proceeds.

     For a period of one year following the closing date, $500,000 of the sale
proceeds will remain in escrow as security for the Venture's agreement to
indemnify the purchaser under the asset purchase agreement.  The Venture's
primary exposure, if any, will relate to the representations and warranties made
about the Myrtle Creek System in the asset purchase agreement.  Any amounts
remaining from this indemnity escrow account and not claimed by the buyer at the
end of the one-year escrow period plus interest earned on the escrowed funds
will be returned to the Venture.  From this amount, the Venture will pay any
remaining liabilities and the Venture then plans to distribute the balance, if
any, to its partners.  From its share of this distribution, the Partnership will
retain funds necessary to cover the administrative expenses of the Partnership
and it plans to distribute the balance, if any, to the limited partners.

     Although the sale of the Myrtle Creek System represented the sale of the
only remaining operating asset of the Venture, and the Partnership's interest in
the Venture represents its only asset, the Venture and the Partnership will not
be dissolved until all proceeds from escrow have been distributed.

     On January 9, 1998, the Venture sold the Clearlake System to an
unaffiliated party.  The Venture repaid a portion of its indebtedness, settled
working capital adjustments, deposited $300,000 into an indemnity escrow account
and distributed the remaining net sale proceeds to the Partnership and Fund 1-B.
The indemnity escrow period expired on January 9, 1999, and all of the $300,000
indemnity escrow amount plus $14,977 of interest was returned to the Venture.
The Venture has distributed these funds 60 percent to the Partnership and 40
percent to Fund 1-B.  The Partnership used it's portion of these proceeds to
repay a portion of its remaining liabilities, therefore no distribution of these
funds was made to the limited partners.

                                       8
<PAGE>

     Because the Venture has sold all of its assets and further distributions,
if any, will be made to the limited partners of record as of the closing date of
the sale of the Venture's last remaining cable television system, new limited
partners would not be entitled to any distributions from the Partnership and
transfers of limited partnership interests would have no economic or practical
value.  The General Partner therefore has determined, in accordance with the
authority granted to it under Section 3.5 of the Partnership's limited
partnership agreement, that it will not process any transfers of limited
partnership interests in the Partnership during the remainder of the
Partnership's term.

RESULTS OF OPERATIONS
---------------------

     Due to the Myrtle Creek System sale on July 30, 1999, which was the
Venture's last remaining operating asset, a discussion of results of operations
would not be meaningful.  For the period ended September 30, 1999, the Venture
had total revenues of $1,384,006 and generated an operating loss of $133,418.
Because of the gain of $6,350,069 on the sale of the Myrtle Creek System, the
Venture realized net income of $6,704,316 during the nine months ended September
30, 1999.

                                       9
<PAGE>

                          PART II - OTHER INFORMATION



Item 6.  Exhibits and Reports on Form 8-K

         a)  Exhibits

             27)  Financial Data Schedule

         b)  Reports on Form 8-K

                 Report on Form 8-K dated July 30, 1999, filed August 16, 1999,
             reported that on July 30, 1999, the Venture sold the Myrtle Creek
             System to an unaffiliated party for a sales price of $10,000,000,
             subject to customary closing adjustments.

                                       10
<PAGE>

                                   SIGNATURES


  Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                       JONES CABLE INCOME FUND 1-C, LTD.
                                       BY:  JONES INTERCABLE, INC.
                                            General Partner



                                       By:  /S/ Lawrence S. Smith
                                            ----------------------------
                                            Lawrence S. Smith
                                            Principal Accounting Officer


                                       By:  /S/ Joseph J. Euteneuer
                                            ----------------------------
                                            Joseph J. Euteneuer
                                            Vice President (Authorized Officer)



Dated:  November 12, 1999

                                       11